[F ROCK]

i just bought a 1975 455 yu; with 6h heads.
pretty clean inside, gonna hone and replace bearings and rings.
has 066 cam.
so i guess i'll be replacing that intake with a performer, or does an older stock intake fit? what about that carb? worth rebuilding? i havent got the number from it but i'd bet you're familiar...
any head suggestions? daily street driver. want reliable, pump gas cruiser; but want more than the advertised 200 horsepower. tight budget too.
could i use #96 heads and o68 cam? can i use my old rockers?
please excuse my ignorance; 1st time engine building. i'd like to hear some suggestions.

on another note...
ive just talked my brother into buying a 65 lemans; (his first pontiac, he's always had chevys).
he was gonna install a 427 chevy in it. that've been o.k. w/ me. at least it'd be half pontiac; but...
then we found an old (69?) wt 400. he's pretty keen on buying this and building it instead. we're negotiating price on this one and i havent seen it yet. finally something in common w/ my brother. i'll get him to sign up to the PY forum; he's not really into computers; or reading much...

[steve25]

Your gonna want to replace the oil pump with a new one that has a thick bottom cover plate, and also install a HD oil pump drive rod.
The 068 cam and stock exh manifolds will be a good choise although there are many better cams for making power that can be had I would say the difference in a new cam pumping thru the stock exh manifolds will not loose you to much power.
The #96 heads with the bigger cam will for sure be a better way to go, as those 6H heads have a huge 124 CC chamber and the smaller 1.66" exh valves compared to the 1.77" in the #96 heads, and yes you old rockers are a drop in!

[F ROCK]

thanks. yeah i forgot to mention that i'd probably add headers. maybe not right away, but in the plan for sure. why the thick plate on the oil pump?

[Mr. P-Body]

F Rock,

The 400 is a much better buy... Blocks are stronger.

Don't worry about the oil pump. The "thick bottom pate" is "old school". The modern Melling pumps are fine. The matalurgy has changed dramatically since the 1960s. The part number you want is M54D-S. IS-54A is also the part number for the oil pump drive.

With those 6H heads, compression is through the floor (around 7.9:1). Power output from that 455 is pretty poor. A head change and cam change would really "wake it up".

The best investment you can make in your Pontiac is to buy Jim Hand's "How to Build Max-performance Pontiac V8s", published by SA Designs. Base your build and decisions related to it on current factual information, rather than old stuff and "myth and superstition". Get yourself educated and make smart decisions!

Jim

[Drew W]

The best investment you can make in your Pontiac is to buy Jim Hand's "How to Build Max-performance Pontiac V8s", published by SA Designs. Base your build and decisions related to it on current factual information, rather than old stuff and "myth and superstition". Get yourself educated and make smart decisions!

Listen to Mr. P-body! He knows his stuff. Read the book, make notes on questions you have (page in the back of book for this) and post your questions in this forum.

I lurked in the forums for months asking lots of questions before building up my 1st Pontiac (455). My copy of Hand's book is well used from re-reading it.

Have fun building your 455.

[77TA406]

Sorry guys...I don't mean to hijack this thread, but I have a question about the oil pump drive shafts. I recently bought a new shaft from a local parts store. I gave them the Melling IS-54A number, but instead they brought me in a Clevite shaft. The Clevite part looks physically identical to the original OEM part, except it is black in color. Is the Clevite part of good quality...is it hardened like the Melling. Thanks in advance to anyone who can answer.
Chris

[rtanner]

ring and bearing that 455, get a 068 cam or a summit 2801, use the 96 heads or get a set of 6x, you will have a mid to low 13sec car no problem! oh and use cast iron 4b intake if you have one if not use the performer,

[1971WARBIRD]

what kind of car are you putting this in?car and trans type make a big difference to cam and head choice.

i did a 73 455 for a 73 trans am several years back.
455 +.030,trw pistons,96cc 4X heads,performer intake,2802 summit cam,complete 2 1/2 dual exhaust,turbo 400,2000 converter,3.08 gears.

ran great,would boil the 275x60x15 goodyears anytime i wanted,idled with a nice lump,if i could keep my foot out of it i could get over 12 mpg.

to have gotten the most out of it i think a conveter that stalled around 2500-3000 would have been better,and a 3.42 gear would have kept it in the power range longer.

just something i did that didn't work too bad.

[F ROCK]

thanks guys, are the 6 x heads more available/ less desirable for my application? i saw a ste of 72 400 heads (kr3?) for sale but i missed em. please tell me about the 6x,
this would be for my 71 gto.
400 trans w/ trans go, has new stock converter(?), 2 1/2" pypes w/out x pipe. not sure what gears in the rear probably 3:08 but i'll be replacing the 8.2 anyway.

[Mr. P-Body]

77,

You're okay. More than likely, it's the Melling part in a Clevite box. Melling is the vendor to a large number of aftermarket suppliers for many parts.

F,

Don't get too wrapped up in "the best" this or "the best" that... The subtle differences between D-port heads are marginal and most can be made to perform as well as any other. The 7K3s are a doorstop, though, unless you're restoring a '72. They have no outboard bolt bosses for exhaust, making header installation a real adventure. This is one of those little things found in "the book". GET THE BOOK!!!

Jim

Drunken Injun is on safari! (we're hunting elephants...)

[Ben M.]

Originally Posted by Mr. P-Body

Don't get too wrapped up in "the best" this or "the best" that...

Seriously, this is it. "The best" is so subjective it isn't even funny. I've never built an engine with high compression (greater than 8.5:1 or more) and have never pushed the limits of pump gas, so almost every recommended "best" part out there is completely wrong for my application as I can't get 93 octane and don't want to watch my timing like a hawk every day when I drive it to work and back. You need to determine what it is that you want the motor to do (complete package with car), read Jim Hand's book (there seems to be a common thread here), and then ask any questions here ;-) Only then can you build a combination that will satisfy you.

Oh, and "tight budget" rarely applies to engines and cars unless you cut some serious corners, which is not advised. Machine work is going to eat a lot of budget, so be prepared to spend a good $2-3k easily just getting a stock engine mostly re-done.

[GR8ONE68]

F Rock,

The 6X heads are very good when done right. I will leave it to the experts on advice as to what to do to the heads for your application, ie. larger exhaust valves, porting, milling, etc. What you do to them should be directly related to your goals. What type of driving, what cam choice, what transmission, what rear gears, etc. It is a package deal and everything should work together.

What I will say is be careful in your choice of 6X heads. For the type of driving you plan on doing, I would strongly recommend the 6X-8 version. This has a larger chamber and is more conducive to street driving than the 6X-4 heads in a 455. Milled down you can "set" your compression to the low to mid 9 range. The 6X-4 is a great head for a low compression 400.

Good Luck

[Rack776]

Originally Posted by Ben M.

Seriously, this is it. "The best" is so subjective it isn't even funny. I've never built an engine with high compression (greater than 8.5:1 or more) and have never pushed the limits of pump gas, so almost every recommended "best" part out there is completely wrong for my application as I can't get 93 octane and don't want to watch my timing like a hawk every day when I drive it to work and back. You need to determine what it is that you want the motor to do (complete package with car), read Jim Hand's book (there seems to be a common thread here), and then ask any questions here ;-) Only then can you build a combination that will satisfy you.

Oh, and "tight budget" rarely applies to engines and cars unless you cut some serious corners, which is not advised. Machine work is going to eat a lot of budget, so be prepared to spend a good $2-3k easily just getting a stock engine mostly re-done.

Sorry to hijack also but there are some knowledgeable people here....

I agree with Ben's reasoning and I read Jims book and plan to stay arround 8.5 to 1
compression with a 75 455 running 72 7F6 round port heads, anyone know what is
a realistic horsepower/torque figure with these parts, reason I'm asking is it runs good now
with the large chamber 6Hs and I can run junk gas in it no problem. I wonder if
the expense of machining the heads & new headders will be worth the power gained
by using the HO heads I have. I like to drive it alot & far so the ability to run pump gas
is very important to me. If I am only going to gain 25-50 HP I'll put the money elsewhere.

What octane would be required to run 8.5 to 1 safely on the street with no fuss,
Jims book states you need a near perfect state of tune to run high compression and pump gas. I usually buy 93-89 octane depending on where I am.

[rtanner]

GET the book, also i wanna say back in the seventies and early 80s we didnt spend hundreds on machine work, we took a running motor tore it down cleaned it polished the crank at home, added aftermarket rod bolts at home in the vise DID NOT get them resized, honed our own blocks at home, put the motors together at home, and guess what, stuck back in our daily drivers, drove em to work, raced em 12-13 seconds, sprayed em nos power shot, and got thousands of miles out of em, car magazines used to have articles aout building at home thats all over now, but you can still do it its called CAR CRAFTING, some call it HOT RODDING, you will be very happy builing a budget combo then beating non budget cars at the track!

[1971WARBIRD]

Originally Posted by Rack776

Sorry to hijack also but there are some knowledgeable people here....

I agree with Ben's reasoning and I read Jims book and plan to stay arround 8.5 to 1
compression with a 75 455 running 72 7F6 round port heads, anyone know what is
a realistic horsepower/torque figure with these parts, reason I'm asking is it runs good now
with the large chamber 6Hs and I can run junk gas in it no problem. I wonder if
the expense of machining the heads & new headders will be worth the power gained
by using the HO heads I have. I like to drive it alot & far so the ability to run pump gas
is very important to me. If I am only going to gain 25-50 HP I'll put the money elsewhere.

What octane would be required to run 8.5 to 1 safely on the street with no fuss,
Jims book states you need a near perfect state of tune to run high compression and pump gas. I usually buy 93-89 octane depending on where I am.

i'm not going to give you a number,but i loved the first round port motor i had.d ports are great,but the added flow of the stock round ports is nice.match the cam to those heads and you'll love it too.stock lift is about .410,the round ports like alittle more.i ran an old crane;218-230 duration,.450-.465 lift.it was a 4 speed with a 3.31 posi.you could take off burning rubber in 3rd gear if you wanted.

[Doug1]

I have several of those 76 motors. One I left stock, since it was numbers matching, the other I built with KRE heads and a roller cam. You can easily double, even triple the horsepower from stock by swapping the heads, adding a better cam and exhaust.

[matrix]

Originally Posted by rtanner

GET the book, also i wanna say back in the seventies and early 80s we didnt spend hundreds on machine work, we took a running motor tore it down cleaned it polished the crank at home, added aftermarket rod bolts at home in the vise DID NOT get them resized, honed our own blocks at home, put the motors together at home, and guess what, stuck back in our daily drivers, drove em to work, raced em 12-13 seconds, sprayed em nos power shot, and got thousands of miles out of em, car magazines used to have articles aout building at home thats all over now, but you can still do it its called CAR CRAFTING, some call it HOT RODDING, you will be very happy builing a budget combo then beating non budget cars at the track!

Agree 100%