How much should 333 heads be milled?

[models916]

Got some 333 truck heads and want to mill them to reduce the combustion chamber. What is the scoop on this head? Any clues on springs. I did buy a 409 crank for my 348 block on ebay yesterday. The heads came from a swap meet. I like to hear all the options before I get to spending money. Thanks all, you have been a big help so far. MIKE

[Ed51]

I don't have a 409 ...yet,but if W-engine heads are flat on the bottom,it would seem to me milling them to do anything other than removing warpage would not make a bit of difference.

[OldTruckNut]

I was wondering the same thing myself. From what I've read, the truck heads are not flat, they do have a small combustion chamber. If it would help the compression, how much you could cut them before the intake gets hard to line up. I'd like to boost the comp a little on my truck 409. I know the pistons are also part of the low compression, but I hate to change low mileage pistons just yet, not to mention the cost.

[models916]

The 333 truck heads have a small chamber. Just wondering if anyone has milled these to lessen the loss of compression.

[johnnyrod]

I have a set of 333s and I took 20 thou off and used steel shim head gaskets to help raise compresion . How much I got I dont know but it is an improvement. I am useing flat top 10 to one pistons and its a car block. A 340 hp cam and tri power. It sounds real good but havnt had it on the road yet. I will let yall know ehn I do. John :D