[Skip Fix]

I've never had blocks side by side to look at and I don't think we've had a thread here where we have had multiple pictures to compare. I didn't originally post the casting # to see what you all thought without prejudice. Now seeing other pictures it looks like the webbing out to the dowels and the thicker pan rails are the tip offs.Be intersting to get some 455s 2 bolts , 2 bolt drilled for 4 and 4 bolt blocks. We can get a data base to make it easier to tell.

I'll have to take a look at the later block I used for my RAIV 400, it was only a 400 hp motor but would spin 7000 with the solid cam.

[Tom Vaught]

The block is the backbone of the engine assembly. Careful selection will get you pretty far on your HP goal as Pontiac Dude (Kenny) said. Bill Jenkins used to talk about small subtle difference in SB Chebby blocks he would look for. With the nice selection of cast iron and aluminum blocks for sale for the Pontiac we at least have a good starting point now. Not a Brad Anderson part for sure, but still a start. It would be nice to post the "Good Blocks" but then the swap meet guys would be asking an arm and leg for them just like the old casting number 37 "ram air" heads vs good old "D-ports" Not much changed in those heads either.

Tom V.

[P@blo]

So the reason why we are sort of dancing around the hard facts is because of a fear of increasing demand and pricing for the "best" blocks ? This gets my panties in a bunch to say the least.

I don't see the point in answering 30% of a question on 20 different threads covering the same subject. We know the 500557 block is weak but what about the rest of the castings.

Dude: Would be easy to take this to the anal level. LOL. Basically there is a really weak casted block late 75 and newer, (reminds me of the 403 Olds units, LOL). Then a decent cast blocks between 71/early 75 and then 3 good cast other blocks 67/74 to choose from for higher hp builds.
But most any of the blocks from 71 thru early 75 will handel 80% of the customers builds.

Brian and Ken, it would be a great help if you would post the block numbers that you would only use for race applications (high HP builds) and the castings that should only be used for moderate power levels. Thanks for posting the 500557's limitations and hope you will be willing to share the rest of the goodies.

[Skip Fix]

But Brian thought this 500557 would be good for splayed caps initially. I think the differences are real subtle unless you know where to look, and even then can be fooled. That's why I think the more pictures the better. There probably are variations in the same casting number, kind of like some of the same 455 codes drill for only 2 bolts, others for 4 bolts.

[David Holmberg]

Skips correct, I've seen 455HO blocks (71-72) that were not as strong as a few 75 blocks. It's not Voodoo or rocket science, it's just a matter of looking for differences in the blocks...

And as soon as someone posted that "***" blocks are weak, everyone using one, or selling one would either be pis8ed or posting "My *** block has lived for 6 years running xx.xx... or the person that has one of the good blocks will be posting that theirs blew up making 500 hp... You can't win.

Anyone today that is looking to make 600+ Hp should be looking at an aftermarket block. IMHO.

[SergeF]

I took some pics of a 70 350 block. To me it's look beefier compare to some 400 blocks.

[70 lucerne lemans]

I have a 70 350 block sitting in my garage also,how far can you bore one?Just curious.
Im glad this post came up,I just wish I had done more research before I built my motor with the 500557 block.Im taking my rotating asy down to Ken this week and letting him build me a stout short block,wish I had done that in the first place!

[Half-Inch Stud]

All these STOCK PMD blocks are like dropping lightbulbs and judging the results. SAET Reference circa 1939: "the picnic egg-toss", presented at the New York Worlds Fair.

Society of Automotive Egg-Tossers.

[P@blo]

That really cleared things up....

[taff2]

The couple of mid 70s 350 blocks I have weigh quite a bit more than the mid 70s 400 blocks I have, the extra weight appears to be in the mains webbing. Shame they can't be bored out to a decent size.

[Brian Baker]

Originally Posted by P@blo

So the reason why we are sort of dancing around the hard facts is because of a fear of increasing demand and pricing for the "best" blocks ? This gets my panties in a bunch to say the least.

I don't see the point in answering 30% of a question on 20 different threads covering the same subject. We know the 500557 block is weak but what about the rest of the castings.



Brian and Ken, it would be a great help if you would post the block numbers that you would only use for race applications (high HP builds) and the castings that should only be used for moderate power levels. Thanks for posting the 500557's limitations and hope you will be willing to share the rest of the goodies.

I'm not a casting numbers geek. I only looked for what Ken advised me to look for when I found my block, and part of that was the extra ribs cast into the wide ribs that run in the lifter valley from the deck to the lifter bores. You want all of these "good" blocks to get scraped up by vendors and put out for sale for $1000 when they're only worth $400-$500, then we'll go ahead and post all of the pertinent info.

[screamingchief]

I gotta agree with pablo here,,,HIS,,,if you dont have anything to add to this thread beyond derision,please MYOGDB...

Anybody who's been here for any length of time knows your the last person here who'll be springing for aftermarket blocks anytime soon.

And again,I'll repeat this:
This is not a stock vs. aftermarket block thread!

So get off the high horse my friend,either add something productive to this thread,or please just STFU,or,,,at the very least keep the snide comments in check.

This is no different than comparing any other stock items like, manifolds , distributors , heads , cranks , transmissions , you name it...

You've done that in the past,so that's all that's going on here,what's the big issue???

I'm not trying to be an a$$ here,but you seem intent on derailing the direction this thread should be going,this thread could be a good means to explore the subtle differences in factory castings,with a good visual database for folks to explore and see these various castings,and their nuances.

But if every few posts is you coming out and poo-pooing all things stock block related it's gonna get real old real soon,seems to me some folks here are real interested in the subject even if you are'nt...

Post some pics of blocks if you got any,that would be productive!
And very welcome!

As for the weak argument earlier about this leading to some dipsh!t at a swap meet wanting top dollar for any good castings,it's total crap,will only happen if the buyer(s) go along with that line of thought,otherwise that sorry a$$ person selling will be stuck lugging that same block to 20-30 swap meets to get his price.

Wont happen...

Besides,I myself have never bought a single block at a swap meet myself,never needed to,bought one set of heads,one time,and those turned out to be big POS.

Never again...

[screamingchief]

You want all of these "good" blocks to get scraped up by vendors and put out for sale for $1000 when they're only worth $400-$500, then we'll go ahead and post all of the pertinent info.

Please explain to me how this is any different than any books already on this subject???

Or any books on other pontiac related subjects for that matter???

Are we to admonish Pete McCarthy,Jim Hand or the guys over at H-O for letting the "cat out of the bag" by their putting that info out for all to see in print?

Is Cliff R. deserving that contempt too for showing all that a Q-jet can be made to run with the best carbs,was he wrong to let others know how and why to do such?

Or is it only OK when somebody is making $$$$ off "spilling the beans" as they say...

Come on folks,like I said,that argument is just weak!!!

Might as well just shut down these boards completely before the last few great pontiac secrets are ripped from the hungry claws of the selfish all knowing pontiac gods...

GMAFB...
Bret.

[Brian Baker]

Originally Posted by screamingchief

Please explain to me how this is any different than any books already on this subject???

Or any books on other pontiac related subjects for that matter???

Are we to admonish Pete McCarthy,Jim Hand or the guys over at H-O for letting the "cat out of the bag" by their putting that info out for all to see in print?

Is Cliff R. deserving that contempt too for showing all that a Q-jet can be made to run with the best carbs,was he wrong to let others know how and why to do such?

Or is it only OK when somebody is making $$$$ off "spilling the beans" as they say...

Come on folks,like I said,that argument is just weak!!!

Might as well just shut down these boards completely before the last few great pontiac secrets are ripped from the hungry claws of the selfish all knowing pontiac gods...

GMAFB...
Bret.

I know of no book in publication that shows the reader where certain "garden variety" OEM-PMD parts are just as good (or better) than their "high performance" OEM-PMD counterparts.

McCarthy's books, although containing tuning tips, are more about cataloging some of the rare and more desirable PMD parts and cars.

Hand's and Ruggles's books are about what can be achieved when fine tuning a combo using OEM-PMD parts.

H-O's newsletters were all about Stock and Super Stock class racing, and how it could be applied to street/strip or bracket cars.

I don't beleive any of these publications have broached engine block selection, at least not in regards to how one would go about determinging which "garden variety" block was better than another "garden variety" block.

[Half-Inch Stud]

screaminchief, I AM on topic.

My EXPERIENCE with looking over stock blocks has reached a conclusion: good luck with thaat.

We balance the CYL wall thickness uniformity with Main Web integrity, and ADD the Cam bearing bore concentricity. If you remain tired of my advice then go-head, learn the hard way.

To DEVELOP this TOPIC:
(A) I have not yet seen a 425A block webbing pictured (well I could have missed it).
(B) 3 Steel Main Caps remain the key Stock block upgrade. How a fell goes about bolting them can be fine or ruinous.

(C) no bean left to spill. My opinion is you could start a block selection with an eye on superior Mains meat, then fail it on CYL core-shift or Cam tunnel bind. Says to me I've been lucky on block selection.

[Half-Inch Stud]

Okay, 4-bolt 400 blocks are the best. WW WS Wt, , even a YD.
Soooo, the crank goes with that: is it strongerr than a 3.25" 103N crank?

10%stronger? maybe.
25% stronger no.
50%stronger: no way.

This thread is trying to resolve a 10% advantage on castings. Yikes. It's ugly.

[PONTIAC DUDE]

I'm not a casting number kinda guy. I just look at things and see what will work for the application intended. I have built 455' with the later 76 and up 400 blocks No problems. And addressing the Best block deal isn't necessary for over 3/4 of the builds out there. Any of the pre 75 blocks will make hp and live.

The Pontiac Block is a weak design, period for todays hp needs to begin with so anything over 500hp is a stretch and your own your anyway. But done constantly.

It's more important to pay attention to building details.

[BruceWilkie]

I recently (and reluctantly) sold a 59 420A block have a 59 389 2bolt block and have compared them to a 69 400 YD block a 70 350 block a 73 400 block and a 76 block. I wish the blocks were close to me(in storage 900 miles away) The 59 blocks are significantly thicker in the main caps webbing and bore areas. The 2bolt and 4 bolt 59 389 caps are approx 1/4" taller when placed next to the later caps and use longer bolts. The webbing is at least twice as thick, the pan rails thicker, cylinder walls (the 420A was .150" oversize! yep 4.21 bore) the other 389 is only .090 over. The downside is the bell pattern and no way to block mount a starter. The 70 350 seems to be a bit better than the 69 yd400 (4bolt block w/2 bolt caps) and looks the same as the 73 400 2 bolt(I suppose you could sleeve the 350 to a bigger bore if you just had to have that stock 350 look). The 76 400 currently in my wifes car is without question the weakest of them all. Wish I had some pics to share.

[screamingchief]

I don't believe any of these publications have broached engine block selection, at least not in regards to how one would go about determinging which "garden variety" block was better than another "garden variety" block.

Yeah,that's kinda true,I see your point Brian,really I do,but should we,the contributors to this thread,be admonished for trying to correct any possible oversights in that respect?

Granted there's a lot of "meaty info" that never gets into these (or any) books or such,as the books stick mostly to the "cream" of the pontiac hi-perf. parts realm,but is'nt that what places like this are supposed to address,shine the light where the light rarely gets shone.

To boldly learn,what's only known,to but a few!!!....
OOPS,damn I'm starting to sound like an old star trek rerun...LOL

IMO this is all relevant data,and as such there are people out there who like to understand what they're dealing with,and what to look for when inspecting these pieces for consideration.

To me this is no different than finding a correctly date coded intake for a specific engine combination during a restoration or such.

To do such almost everybody relies on some sort of base of reference for determining the quality of the info at hand.

It's just that it amazes me why anybody would be so over-protective of this kind of info in the first place if it's like some here keep trying so hard to convince all the rest of us,that it's this "non-issue",like it's something that's not worthy of even considering...

Then why not part with the info???

Folks,here's a little experiment,,,try telling your wives (or friend,or such) you got a secret,but that it's not important enough for her (them) to know and see how well that goes over with her (them)...

Perfect way to drive them crazy,right...

HIS,I gotta admit I probably came off a bit harsh earlier,sorry 'bout that,but in this thread your tendency has been to jump in and make a few cryptic comments that come off in a sarcastic manner,and then duck out without really adding much,it just seems to me that it distracts from the main topic,but hey,,,that's cool I guess,,,it's a free world right...

My EXPERIENCE with looking over stock blocks has reached a conclusion: good luck with thaat.

See it's comments like this that beg a response,something like:
"Soooo what are you building these days HIS???
How many IA-1,IA-II,MR-1 combos do you have???"
Yeah,,,good luck with thaat indeed...

How a fella goes about bolting them can be fine or ruinous.

Again,in the past you've made your views on that subject known,and I've never ridiculed or derided you for them,even though plenty others may have,and there are tons out there who use studs contrary to your preference for OE bolts.

But these are the type of comments that can detract from the point at hand,how does any of this stuff further this topic???

Again,not trying to be a d!ck,,,but just trying to make a point,,,can you see what I'm getting at here???

You mentioned the 425A,so that's what you want to see,wish I could help you there,but alas,seeing as how I dont have one,I cant help ya'll with that one myself,but my question in response to that would be this,how many folks you think are going to go thru the trouble to dig one of those up,and then adapting it to fit into a late model chassis???

Probably not very many,but if this thread keeps one person from blowing up their $#!t by putting together an engine with weak block like those "thin web" blocks,then this thread has been worth it IMO.

I know what your talking about with regards to the earlier blocks though HIS,they have the rib that runs parallel to the pan rail on the one side,and they are pretty meaty,think they carried some of this over into a few of the later programs like the RA V program,some of that stuff in is pictured in the McCarthy books.

Sometimes 10% stronger is what it takes to survive,,,at least for some...

I welcome any and all pics myself though!!!
The more the better,new blocks,old blocks,oddball blocks you name it!

If even a fraction of the forum members posted just a couple pics of their blocks just sitting around in a thread like this,the resulting value to all would be imense IMHO.

I did what I could,took the pics,gave the info,and put them here for all to see,hopefully more will do the same,like to see this one grow a life of it's own,but that'll depend on all the rest of ya'll.

I'm gettin down off the soap box now folks,the ball is in ya'lls court...


Bret.

[Brian Baker]

Jesus, Bret (LOL). Selecting a good block on the level you're looking for 'Dude, or myself, or anyone to explain to you is a little more involved than decoding casting numbers, and is hard to define with pictures and text, because there are so many variables to deal with. I mean for years, we were told a '70 455 was the holy grail of all non-SD blocks, but what we've found through research of blocks (and not neccessarily casting codes) is that some later blocks are just as good, and in some cases, a better casting.

I think you've got some good tips to go by already on this thread alone. The next step if you want to really get anal is to bring a micrometer and a ruler along with you the next time you inspect a potential block for purchase.