All I can say is that my 454 with 9" street tires and about 80lbs more than your can breaks them loose at 35mph and sometimes at 40mph going WOT. And it's not like it's that radical of a build either.
The axles are from superior. I bought them back in 2003. They were supposed to be a direct replacement for a 7.5 26 spline rear. However when I got them they either had 31 or 33 teeth on them. When I ordered the posi from auburn I asked if I could get gears to fit those axles and they said no problem I put it all together with new bearings & seals and everything fit like a glove. I don't know if you can even get those axles anymore. Another thing I did was use a 3:08 and lower carior? and put 3:42 gears on it. It has a thicker ring gear that way. I have also heard that this rear will not hold up to 12's & lower. Thinking about a strange with the new engine.Yeah, the factory posi's are weak, the side and spider gear teeth are real fragile.
Care to share how you got 31 spline axles into a 7.5"?? No one makes them, or a posi or spool to fit them, and that size axle won't even fit through the carrier bearings on each end of the differential for that matter.
Biggest axles that will fit through the bearing are 28 spline, up from the factory original in your G-body of just 26 spline....but even then, with 28 spline axles the axles aren't the problem....you get this down into the high 12's at the strip and it's going to start peeling ring and pinion teeth off(pinion stem flexes due to small size and gear mesh goes all to crap and crunch ), and there ain't no heavy duty fix for that except an entire rear end swap to something that will handle the power....12-bolt, 8.5" 10-bolt, Ford 9", custom Dana 60.
There's a reason GM put the 8.5" in turbo Buick G-body's, looks like you're about to find out why with the new engine ain:
The heads have raised exhaust ports. The chambers are 112cc and everything is cnc machined. This engine will be in a 1984 G-body. Space is at a premium in one of these too. I don't plan to rev it to the moon. I'm looking at a custom street grind cam where I'll be shifting at about 5500 rpms. I would think a cast steel crank will be fine for my application. High rpm horsepower isn't my goal. I like my peak torque to hit by 4 grand and a lot of it. For me that's the fun stuff for a street vehicle with a occasional pass down the 1320.If you're not gonna rev it to the moon, either should be fine. If you are, forged crank just to be safe, they aren't too terrible more expensive.
My 496 has 20cc dome pistons on zero deck, the heads have 119cc chambers, comes out around 10.3:1 iirc. Mine is in a 445 casting block and did not require any clearancing.
Are those heads"raised exhaust port" heads? If so, don't be surprised if you have to smash a header tube or two. I have race rite ovals, and darn glad they are stock exhaust port location heads, driver side header barely clears everything, passenger side looks to have way more room for stuff. This is in a mid 60's a body though, not much room for anything.
I have 30 spline axles in my 8.5" rear in my S10. Used to have an Eaton clutch type posi until I destroyed the spider gears in a 2900# car with a 383 and slicks. Now I have a spool, c-clip eliminators, and one of those covers that supports the carrier bearing races. A 7.5 posi behind a big block in a heavy car is just waiting to break. Better a 12 bolt or a 9" rear. What I would have done if I didn't have so much money in the one I had already.I would like to make a correction about the axles. They are 30-spline, not 31 or 33. They were an option for the 8.5" 10-bolt. You can get 30-spline side gears for the 8.5" carrior which are also the side gears in my 7.5" custom Auburn posi. Everything fits like a glove. BTW moser makes these axles too.
Anyway, getting back to the topic at hand, If I do go with the 496 build what are the clearance issues that might arise?
ericnova, that's exactly the kind of info I was looking for! I was leaning towards Scat anyway and your post helped me with my decision.SCAT is also Chinese sourced forgings and castings, but SCAT does finish machining here in the US whereas Eagle doesn't.
Most all you crankshaft companies entry level stuff is cast or forged in Asia..Callies CompStar, Molnar, Ohio Crankshaft, along with SCAT and Eagle.
The better companies just do the final machining here in the US, so they can control finish quality.
I like SCAT over Eagle....but Eagle has improved from their earlier problems with sizing and finish and don't appear to have the same problems and poorer reputation they once had.
Stay away from CAT though(Cal Auto Transpeed), very poor quality and finish on the cranks I've seen.
Current unknown on exactly how good the quality is happens to be SpeedMaster(ProComp)...some of it is Ok, some is poor, but it is steadily improving in most cases.
I don't personally know anyone who has used their cranks or pistons....but their connecting rods or decent. You can get the rods fairly cheap, but with questionable Chinese bolts in them...by the time you add replacement ARP bolts and pay for a roundness check on the bores after adding the better bolts you are getting close to SCAT or Eagle price territory.
For your plans, the SCAT or Eagle cast crank would work out fine. I recommend forged pistons to everyone who askes about a stroker, I just think it is good insurance as strokers are never driven by a grandma, they are driven fairly hard and forged pistons give you a wider tuning window along with room to grow down the road(nitrous, bigger cam, more rpm) as hot rod stuff often evolves as we change our minds on what we want or get greedy about power.
This is the best deal on stroker kits I've found as it includes harmonic damper and flexplate and has a special forged piston...you can find cheaper but they typically leave pieces out or use lower grade components or hypereutectic pistons to get that lower price point.