[tempest1964]

Is someone having a bad day?

[Tom Vaught]

Originally Posted by gavin

Steve you are correct about post 63 blocks but the 61-62 blocks come in at 187 ibs compaired to a 69 400 block at 177 lb and 455 block at 181 lb. They took some meat out after 63. Fast 69 posted that 59-60 blocks were 184 lbs so the 61-62 blocks have more meat than those as well.

Depending on when the specific block was poured some blocks will be heavier vs others.
10 pounds difference on the 61-62 blocks seems a bit light to me.
The early 59-60 blocks being even heavier. I have measured a couple of 61-63 blocks on a shipping scale that were over 200 pounds.

That being said, having more metal in the block but in the wrong spots doesn't buy you much. I have posted in the past the 67 400 blocks were a new design and the factory engineers were conservative about making sure they kept the strength in the block.

Later blocks you can look at how the blocks were made and see the changes that allowed them to pour the blocks easier vs focusing on the strength part of the design.

It was assumed that a very early 59-60 block might be in service for many years and have several rebuilds (rebores). Kind of like a IA-2 block where you can assume you would get 5 rebores out of the block if you started at 4.181" bore size. Cylinder walls were thicker.
A Rib added to the lower case, etc.

So you need to look no so much at the weight vs how the 63 to 76 blocks were cast up.
10 lbs in weight is just noise in the system.

Tom V.

[hurryinhoosier62]

Originally Posted by Tom Vaught

Depending on when the specific block was poured some blocks will be heavier vs others.
10 pounds difference on the 61-62 blocks seems a bit light to me.
The early 59-60 blocks being even heavier. I have measured a couple of 61-63 blocks on a shipping scale that were over 200 pounds.

That being said, having more metal in the block but in the wrong spots doesn't buy you much. I have posted in the past the 67 400 blocks were a new design and the factory engineers were conservative about making sure they kept the strength in the block.

Later blocks you can look at how the blocks were made and see the changes that allowed them to pour the blocks easier vs focusing on the strength part of the design.

It was assumed that a very early 59-60 block might be in service for many years and have several rebuilds (rebores). Kind of like a IA-2 block where you can assume you would get 5 rebores out of the block if you started at 4.181" bore size. Cylinder walls were thicker.
A Rib added to the lower case, etc.

So you need to look no so much at the weight vs how the 63 to 76 blocks were cast up.
10 lbs in weight is just noise in the system.

Tom V.

Excellent post, Tom.

[MarkS57]

Originally Posted by hurryinhoosier62

Huh? The '59-'60 389 and the '67 400 blocks are known to have the thickest cylinder walls and heaviest bulkheads of any production Pontiac blocks. Mine weighed in at 225lbs when shipped (210 for the block, 15 for the pallet). A member on here bored a '59 389 to 4.250" (+.190 over stk) and still had acceptable cylinder wall thickness. Another member ultrasonically tested a '67 400 block and found it to have cylinder walls at more than .200 thick(non-thrust side) before boring.

Wow, I read a Hot Rod (or CC?) article years ago saying the '73 400 481988 was one of the best blocks for racing due the thick cylinders walls, it was an article about a guy that raced blown 455's I think.

[Tom Vaught]

Originally Posted by MarkS57

Wow, I read a Hot Rod (or CC?) article years ago saying the '73 400 481988 was one of the best blocks for racing due the thick cylinders walls, it was an article about a guy that raced blown 455's I think.

Like to know who that guy was as the number of people running boosted engines years ago was a extremely small number Maybe 5 guys total.

Marty P, The Butlers, John Welter, Mike Cooper, and Steve B out west.

Tom V.

[MarkS57]

Originally Posted by Tom Vaught

Like to know who that guy was as the number of people running boosted engines years ago was a extremely small number Maybe 5 guys total.

Marty P, The Butlers, John Welter, Mike Cooper, and Steve B out west.

Tom V.

I still have the mag somewhere, I'll dig it out when I have a minute. I think he was somewhere in Kansas Or Nebraska? Don't think it was Mr. Butler.

[Tom Vaught]

Only Blower Guy in Kansas was Mike Cooper.

Tom V.

[hurryinhoosier62]

The 4819188 blocks are decent, but the '59-'60 389 and the '67 400 blocks have much thicker cylinder walls and bulkheads. The only problem with the '59-'60 389 blocks is you have to use an adapter to utilize modern transmissions. Never rely on Hot Rod or Car Craft for accurate info on Pontiacs...

[MarkS57]

Originally Posted by hurryinhoosier62

The 4819188 blocks are decent, but the '59-'60 389 and the '67 400 blocks have much thicker cylinder walls and bulkheads. The only problem with the '59-'60 389 blocks is you have to use an adapter to utilize modern transmissions. Never rely on Hot Rod or Car Craft for accurate info on Pontiacs...

Found the mag, I was incorrect, this was a CC article about building a stout 400 written by Marlon Davis with Dave Bisschop of SD in '98 so I believe that's a pretty good reference. The blower article is another article which was pretty cool, I have that one somewhere around here, I'll find it eventually.

[hurryinhoosier62]

For a "stout" 400, a 4819188 block is perfectly acceptable as long as it passes both magnaflux and ultrasonic testing; however, you might want to ask Tom V. about his findings in regards to the '67 400 block. Paul Carter (gtofreek) is another source on the superior cylinder wall thicknesses found in the '67 400 block. As for my '59 389 block, the non-thrust cylinder walls average at .185-.195. In otherwords, a .120-.170 overbore is possible. You won't find that in 4819188 blocks...

[Tom Vaught]

There are lots of post out there in the PY Search Engine about the difference between the different engine blocks. Paul Carter is a sharp guy with Pontiac engines and engine building as a occupation.

Pontiac changed the whole sand mold casting configuration when they went from the 2 freeze plug design blocks to the 3 freeze plug blocks. Inspection of two blocks, of different years, will show the attributes of the 1967 block, especially the two bolt drilled main block (which can be adapted to the splayed cap configuration) like Pontiac (Tom Nell) did for Arnie Beswick's Supercharged engine program.

Then you have actual testing at 1600 horsepower for 3 years (Palbykin Testing) and several "mistakes" in the tune-up during that time with the block still living for 3 years.
Also the first "Normal" production cast block that ever ran in the 6 second time class.
Arnie was there with his Tom Nell Experimental Blocks which you can assume were really robust. RA-V Lifter Bracing, etc.

But everyone has to make their own decision on this deal. Otherwise we are just confusing the issue further.

Tom V.

[gavin]

Good posts guys I will now have to get the block soniced as I am now quiet curious about the wall thickness. The basic block is interesting as its a 421/sd block with 3" mains and has all the good bits b-man pointed out.I wasnt saying its better than a 67 or 59-60 block just thats it likely to be a pretty good base compaired to later 389 blocks. I have it sitting beside some 68-69 blocks and a 455 block and everthing looks some what stonger. Of course as tom said if its in the wrong place it wont help.I will try to get the block soniced this week and will put the sheet up on the board.

[gavin]

Just for a comparison b-mans 421 shots to 62 389

[gavin]

a few more

[gavin]

The rest

[johnta1]

Wow, I read a Hot Rod (or CC?) article years ago saying the '73 400 481988 was one of the best blocks for racing due the thick cylinders walls, it was an article about a guy that raced blown 455's I think.

Probably Barry Mehring.



More than 5 probably running boosted and not NOS back then.
I think John Welter was NOS back then along with one of the Butler's.

[gavin]

The engine shop is busy so sonic will be one to two weeks but here is some info from the 2nd book of pete mcCarthy. Note the same block is used for the 425a engines.The sonic info will follow as soon as I get it . If you are wondering why I am floging this dead horse we seem to be down to the 67 engine as the only sorce of a 3"main block with a late bellhousing that can take a real beating. I would like to put this block beside a 67 block to compair bulkheads ect but my 67 block is still in my car. I think there proberly as many 538181 blocks out the as there are 67 blocks. As soon as the sonic comes back we will know all and it may be that I am wrong and that they are of small intrest.

[Tom Vaught]

Originally Posted by johnta1

More than 5 probably running boosted and not NOS back then.
I think John Welter was NOS back then along with one of the Butler's.

Welter ran a Supercharged Engine long before he ever went to the Turbo Stuff.

Think the Supercharged Car was the one he had his bad crash in.

Learned something on the 389 SD Blocks, that they and the 61-62 421 SD block were the same block casting, no Pyramid on the back.

Tom V.

[tom s]

A 366 NASCAR block is the block to find.Had a stock 4.155 bore and 3 in main.Heavy walls and joined lifter bores.Tom

[gtofreek]

Originally Posted by tom s

A 366 NASCAR block is the block to find.Had a stock 4.155 bore and 3 in main.Heavy walls and joined lifter bores.Tom

Yeah, but how many dozens of those did they make, and are still left out there?