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  #1  
Old 03-09-2008, 05:55 PM
JeepsAndGuns's Avatar
JeepsAndGuns JeepsAndGuns is offline
AMC 4 OH! 1
 
Join Date: Jul 18, 2003
Location: Cullman, AL
Posts: 4,575
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.
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79 Cherokee Chief 401/T18/D20, MPFI fuel injection, hydroboost, otherwise stock.
Future mods: Caddy 500/NV4500/NP205, HP D60 front D60 smooth botom rear, 5.13 gears, 35x12.50's on H1 beadlock wheels. Warn M12000 winch.
93 Wrangler 4.6 stroker/AX15/NP231,SYE,CV, OME 2.5 lift, front hub conversion/big brakes, 31X10.50's Warn M10000 winch.
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Old 03-09-2008, 06:03 PM
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mafos4471 mafos4471 is offline
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Just a reminder to shave the intake manifold the same amount. Most machine shops will know how much you can go without problems.
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  #3  
Old 03-11-2008, 06:25 PM
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JeepsAndGuns JeepsAndGuns is offline
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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.
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79 Cherokee Chief 401/T18/D20, MPFI fuel injection, hydroboost, otherwise stock.
Future mods: Caddy 500/NV4500/NP205, HP D60 front D60 smooth botom rear, 5.13 gears, 35x12.50's on H1 beadlock wheels. Warn M12000 winch.
93 Wrangler 4.6 stroker/AX15/NP231,SYE,CV, OME 2.5 lift, front hub conversion/big brakes, 31X10.50's Warn M10000 winch.
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Old 03-11-2008, 09:48 PM
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mafos4471 mafos4471 is offline
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Ahh.. start at .040 or less anyway... I thought I heard something on here before about this.
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  #5  
Old 03-12-2008, 07:00 AM
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Serious Johnson Serious Johnson is offline
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Join Date: May 19, 2002
Location: Pumpkintown, South Carolina
Posts: 3,831
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.

S.J.
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360, .030-over, K8600 cam, Crane springs, ported heads, Edelbrock Performer, G.M. TBI, TFI, 3" exhaust,
T-18a/208, D44/AMC 20 w/ limited slip in both, 3.73s, 33s, BDS 4" springs, Rancho 9000 shocks, etc., etc.
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Old 03-12-2008, 04:48 PM
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JeepsAndGuns JeepsAndGuns is offline
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Join Date: Jul 18, 2003
Location: Cullman, AL
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Thanks!
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79 Cherokee Chief 401/T18/D20, MPFI fuel injection, hydroboost, otherwise stock.
Future mods: Caddy 500/NV4500/NP205, HP D60 front D60 smooth botom rear, 5.13 gears, 35x12.50's on H1 beadlock wheels. Warn M12000 winch.
93 Wrangler 4.6 stroker/AX15/NP231,SYE,CV, OME 2.5 lift, front hub conversion/big brakes, 31X10.50's Warn M10000 winch.
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Old 03-12-2008, 05:34 PM
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fulsizjeep fulsizjeep is offline
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Join Date: Aug 21, 2002
Location: Jubilee Jeeps.SWCO
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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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88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s with a few Evil Twin & TT's Fabworks mods
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