FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: fomocoloco on September 12, 2026, 11:43:49 AM
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.040 over block . all machine work done. decked, bored, honed, freeze plugs, cam bearings, and painted. clean as a whistle and painted. just wondering whether to build a rather bland 428 stock like build or to go with a stroker kit with a pump gas type build. cast iron heads or aluminum. thanks, i dont need the last 1/2 hp. thanks.
jim oberg
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I've done some 600+ lower rpm stroked 390/428's like that without needing crossbolt mains, etc. I feel comfortable with 600 hp on a factory block without extra stuff done.
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I am following this as I similarly have a 428 block (C marking, I believe it is a 68' vintage) I would consider using for an upcoming upgrade/build if the cylinder wall thickness and main webbing mag test look good. When I previously tried to discuss the idea I felt a little blown off when basically told pretty much "nearly all those are cracked, I wouldnt bother."
Back in the 1970's when I was first messing with FE's the general consensus seemed to be that you were pushing your luck going beyond about 650 HP. But of course HP is really not the determinjng factor, and we were building very different combinations with very different parts back then.
I am under the impression keeping the RPM down and taking advantage of better modern heads should get you into the 550- 600 range with far less stress than how we tried to get there back then...
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Well, that was the caveat…the block needs to be in good shape. A lot of 428 blocks are susceptible to cracks. Gotta be diligent.
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I have some A's out there with lots of miles at 550-585 HP. No issues
Cylinder thickness needs to be enough, that number seems to be different with everyone, but A's are some of the worst for core shift, so have it mapped. C's are usually the best
Where I really see issues are often #2 and #4 mains cracking at the main bolt holes and almost always caps loose in the registers.
As Brent said, got to be diligent. Pay for the sonic map, mag and pressure test and don't take shortcuts
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my427stang,i had an original 68 1/2 cobra jet fastback that had the no 2 main with a large crack in the threads.lost oil pressure.everything else was nice,but a mostly stock engine.junked the block,later sold the car.
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I think with proper prep, the A scratch is safe at 600 hp, provided that it lives in an otherwise healthy environment. Do your diligence re cylinder wall thickness. Being out of balance or detonating might get a block blamed for another problem. Sometimes a cylinder splits because it is thin, and sometimes because it is mistreated. In my life, I have seen more cracks in 428 cranks. Hardly ever in the internally balanced ones. Same goes for mains. Many more cracked 428 blocks between the cam and crank bores, almost always #2 and #4. Bad register and cracks in the bolt holes………detonation and/or out of balance.
The ARP main studs for FEs are not good. You are better off with bolts. Older studs had a lot more thread engagement on the block end.
Free public service announcement…….if you stud an FE block, use the 351W stud, and bottom tap the holes in the block. The Windsor studs have more thread engagement. The holes in the block are not tapped to the bottom. You can stud five #5 FE mains with one set of Buick Nailhead studs. It is an easy spot face job to get the nuts slightly below the pain rail and use the Nailhead studs in #5. So four sets of Windsor studs and one set of Nailhead studs does five blocks with no leftovers. It generally does not hurt to leave bolts in #5 if you don’t want to deal with the spot face. Just align hone with it set up that way.
The deaper you can root the stud, the better. Hone the cylinders after that is done, and hone with the mains on it, and torqued. You will get better cylinders that way for a few reasons.
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ALL I CAN SAY IS "WOW". that is the voice of experience. thanks. i'll sell the last std crank i have and buy a scat stroker kit and run with it.
jim
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You can order specific sized ARP studs through McMaster-Carr in any quantity. I ordered a handful of 3/8" studs for the intake / exhaust manifold on my 327 Packard from McMaster-Carr a few months ago. Didn't need anything special, just the needed them to be the right thread pitch and length. Was quite surprised when I opened the Box and they were labeled "ARP" on the top.
https://www.mcmaster.com/products/threaded-rods/thread-adapters-2~/hex-drive-thread-adapters~~/ (https://www.mcmaster.com/products/threaded-rods/thread-adapters-2~/hex-drive-thread-adapters~~/)