[Half-Inch Stud]

Jim, that is helpful.

My point is made then: the subtle differences do not represent enough of a design difference to say this or that block is the capable 700+HP foundation.
Rather we're beyond the paltry 80's & 90's dreadblocks. IA2s, MR1s allow the CHOICE to build upon a stout block. Seems the Billet crank is also a CHOICE.

Looks to me : 700+HP builds WILL require ~$5000 in the Block&crank for some peace of mind.

[screamingchief]

I did'nt think this thread had anything to do with 700+ hp block choices,more like those intermediate choices between what is suitable to use for a stock 250-300 HP build,what is suitable for the intermediate 350-600 HP builds and NOT those said 650-700 and up HP builds.

You know,to help keep folks that are new to (or unfamiliar with) pontiacs from sticking they're nice new stroker crank bottom ends in a weak "late" block and having it nuke itself even though it's only making 450-500 HP...

If those here cant see the obvious weakness in the design of the #500557 block castings,then I dont know what to say,just give up engine building and leave it to those who know what to look for.

If I had a better selection of the "late" 455 blocks,like those Brian and Dude keep refering to I'd be inclined to shine a magnifying glass on that subject too,but my 455 selection amounts to 2 right now,and one of those is in a car already,and it's an earlier block anyhow,so that would'nt help much with this project.

I just felt this would be a good reference for STOCK block comparison,a databank one can tap so they can see what the differences are between various castings.

Not another excuse to start a stock block vs. aftermarket block debate...

[PONTIAC DUDE]

Originally Posted by screamingchief

I did'nt think this thread had anything to do with 700+ hp block choices,more like those intermediate choices between what is suitable to use for a stock 250-300 HP build,what is suitable for the intermediate 350-600 HP builds and NOT those said 650-700 and up HP builds.

You know,to help keep folks that are new to (or unfamiliar with) pontiacs from sticking they're nice new stroker crank bottom ends in a weak "late" block and having it nuke itself even though it's only making 450-500 HP...

If those here cant see the obvious weakness in the design of the #500557 block castings,then I dont know what to say,just give up engine building and leave it to those who know what to look for.

I just felt this would be a good reference for STOCK block comparison,a databank one can tap so they can see what the differences are between various castings.

Ditto.

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.

Making 350 or 360hp with the 75 and later units isn't an issue with the right parts and prep.

[PONTIAC DUDE]

Also remember that the pre 69 blocks only have 2 motor mount attachement locations. And can create an issue in the later 70 and newer body styles as far as support with adaptors.