[Twistedpinion]

Bret-
Kind of embarrassing typing this since I'm asking for input and I'm causing the confusion since I can't read part specs.

The crank is in fact the Ohio 4.21" stroke with 3" mains. I checked the part on the living room floor. I just read the wrong description yesterday when reading the website yesterday.

I had the same concern with those springs yesterday after reading through a bunch of the threads I found here on the site. Funny thing is though, they aren't too far off what Comp Cams calls for with their HR cams. I'd rather worry about getting the right cam though rather since I do have another motor these springs will work in, so I won't be "out" anything if I end up buying another set of springs.

Again, thank you for the input.

Johnny,
This is a 557 block. From what I've been reading though, it would take a good amount more power than I'll be making to split it. As you said, you've been racing yours with out incident for some time and I know of a few others that are making similar horsepower to my goal and have been for years.

I do also have my W72 'XX' block that is numbers matching for the car, but I was planning on tucking that one away in case I ever wanted to do a factory correct build. Thoughts?

Thanks again

-Sean

[74Grandville]

use the XX block and get rid of the 557.

not sure the 557 is going to like the longer stroke.


If i was going to use the 557 I would keep it a 400 and keep the power below 375hp as experts have stated in other posts.

[tom s]

if you are going to do any serious racing then dont use the 557 block.With just street driving and RPMs under 5500 you should have no problems.SHOULD is the word.I built a street motor with the samr block,crank and light weight pistons and rods and made 585 HP at 6200 on the dyno.When it goes in the car it wont see 3000 more than a couple times a year.Tom

[PONTIAC DUDE]

Keep the hp in the 375/390 or so hp and you should be OK with the 557 block. But bottom fill it. stud it and have it align honed. Also make sure it has solid dowels in the main saddles.

[Johnny406]

Originally Posted by Twistedpinion

Johnny,
This is a 557 block. From what I've been reading though, it would take a good amount more power than I'll be making to split it. As you said, you've been racing yours with out incident for some time and I know of a few others that are making similar horsepower to my goal and have been for years.

I do also have my W72 'XX' block that is numbers matching for the car, but I was planning on tucking that one away in case I ever wanted to do a factory correct build. Thoughts?

Thanks again

-Sean

-Sean,

If I knew then what I know now, that 557 block wouldn't be in my car and it will be out in a couple of weeks for the new 455. I'm going to tear it down and inspect it real hard. If it checks out, that motor will then become the spare or will go in the red 81 as a street driver.

For peace of mind, I wouldn't do it.

[steve]

I'll get back to you guys on the 557 deal. Just put a 500+HP 557 into service.

[screamingchief]

Hands down I'd use the XX block for this.

I dont touch the 557 blocks at all.

Never have,never will.

I have 4 400 cid engines/blocks around here,not a single 557 among them,1- 9799914 (70 YS),2- 481988 (73 XN/74 YH),1-481988 (74 YF).

Have 1 455 cid engine that's in my '72 bird (that's a 485428 casting,'71 or '72 YC code).

Me personally,I'd build a 3" main 4" stroker 350 cid block combo before I'd build a 557 block/stroker combo.

Matter of fact I have a '72 350 cid shortblock that's just sitting around here doing nothing,that one came outta the '72 bird (IIRC this one is 481990 casting,with YR code).

This just so happens to be one of the earliest things I learned about building "fast" pontiacs,that info was not so much about the webbing issue itself,just that the mid '70 up blocks were weaker in many ways than the earlier blocks were,and since then I have always avoided the later blocks as SOP.

Yeah,there's been some heated debate on this here,I really dont care what anyone else has to say on that deal,I build my stuff as I see fit,not how someone else tells me to build 'em,so I also try not to tell other folks how to build their own stuff,rather I just tell them what I would do,and leave the rest to the other fella to decide for themselves.

Me,I just cant afford to throw good money after bad,it's that simple.

That and I've never had even the slightest bit of trouble finding plenty of the earlier 400 cid blocks/cores to build.

More than once I've had them given to me just to get them outta someone else's way.



Bret P.