Shaved 360 J heads.

[MoparKid72]

I have a 360 with stock J heads with the big ports. Could I shave these to bump up compression without having any clearance issues? Is there anything else I have to worry about with shaved heads?

Thanks,
Dillon

 

[rob_robinson87]

What are you putting them on? A 318? 340? 360? That will make a difference.

 

[rob_robinson87]

Nevermind... I read it wrong... lol. A 360- duh...

-Yes, you can shave the heads to raise compression. If you get radical with the cut, you will also need to shave the intake and get custom pushrods.

 

[MoparKid72]

Say I wanted to get 9.5:1 instead of my stock 8.4:1. How much would they have to be cut?

 

[7e5hangten360]

a .060in. cut will approximately raise your compression ratio by 1 point. make sure your machine shop removes .095 in. off the intake side of the heads for each .100in. they remove from the head face (.057 for a 060 cut). also, after the heads are cut, when bolting the intake back on the engine, throw away the cork end gaskets and use silicone on both ends of the intake, as the intake will sit lower on the block (or at least copy the end gaskets in a thinner gasket material) , otherwise the intake wont ``sit`` well.

 

[RustyRatRod]

Say I wanted to get 9.5:1 instead of my stock 8.4:1. How much would they have to be cut?

First off, what you need to do is blueprint where you are NOW. Most of the time you'll find the "stock" compression ratio to be much less than what was specified. Sometimes as low as into the 7s. So, you can see that that would require a TON of milling to make up that much difference. You need a baseline from what you have. Because if it ends up being too much to mill, you'll need to think about new pistons and or different heads.