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JeepsAndGuns 03-09-2008 05:55 PM

shaveing the heads
My 401 busted a valve spring a few weeks ago. So I figured I would use this as a opportunity to upgrade. Instead of replaceing just the one spring, I have a couple of other problems that could be either a burnt valve or warped intake sealing surface.
So I figured I would find some used heads, rebuild them, and while I was at it, I would do a little port and polish work. I am also thinking about haveing them shaved a bit to bump the compression. Once summer rolls back around and I start makeing some more money, I would like to convert to propane. So I figured a small bump in compression would help things. Untill then I would just run high test.
My question is, how much can the heads be shaved before you run into problems. Mainly valve to piston clearance and pushrod length. The 401 is 40 over with stock style pistons, and a comp 256H cam. I rebuilt it a couple years ago and it is still in great shape. I also bought a new set of valve springs for the new heads I have. I figure that $65 is worth it, just so I dont have to worry about another one breaking.

mafos4471 03-09-2008 06:03 PM

Just a reminder to shave the intake manifold the same amount. Most machine shops will know how much you can go without problems.

JeepsAndGuns 03-11-2008 06:25 PM

Yep, intake is part of the job, just forgot to mention it. I just didnt know if someone on here might know the ammount they could be shaved and still be safe. Incase the local machiene shop doesnt know AMC's very good.

mafos4471 03-11-2008 09:48 PM

Ahh.. start at .040 or less anyway...:D I thought I heard something on here before about this.

Serious Johnson 03-12-2008 07:00 AM

Shaved mine .040" (360 w/ K8600, Crane springs-retainers, stock-length pushrods, stock bridged rockers, Summit lifters). I knew that mine had not been shaved before, and a local race shop agreed that this amount was safe. I cc'd the chambers & measured v/p clearances w/ clay, but that was years ago and I've lost the numbers.


JeepsAndGuns 03-12-2008 04:48 PM


fulsizjeep 03-12-2008 05:34 PM

I had the heads on my first 401 shaved .030" years ago and did not need to modify anything else for the intake fit OK.

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