ok, bare with me on this, I am kinda new to all this motor work stuff.
I have 01 5.3 truck motor that I am putting in my ZR2 that will be using for rock crawling, trail riding, and just some beach driving...not much racing, since the truck has 42" tires...ha ha
ok, I purchased a 03 LS6 cam/springs to replace the stock cam and hopefully gain a little more power. while I was trying to remove the cam, I managed to mess up a few of the cam bearings ..since I am taking it to a local shop to have the work done, I was thinking of have the heads milled to gain a little bit of compression...I am getting the work done very cheap, so I was thinking this would be a great way to gain a little more power, since it is all apart anyway.
what I am wondering is how much to have the heads milled andI dont want to have issues with the intake fitting right. Also, what about the pushrods, will the stock 5.3 rods work or will I need new ones? so I am hoping you guys could help me!!! I tried searching and came up with very little info on this...maybe I was using the wrong choice of words....dunno. I also posted this on car side of this forum and havent gotten any help..

thanks in advance

Brian

 

mill .050 or take .030 off and use a tighter gasket gasket, going with a smaller quench is the better option but if your on a budget and don't want to shell out the bucks to cometic just take it off the head.

Replace the pushrods with hardened ones the lifters will soak up any amount off the heads.

Dont forget you need the ls6 springs

 

thanks for the reply...
I talked to a guy at the machine shop and he said that .0015-.0020 woudl be plenty? figured that would bring the compression up about a point or so...does that sound right?
thanks again.

Brian

 

I think youve got an extra 0 in there. The rule Ive heard is for every .006 off you reduce the chamber by 1cc in order to raise your SCR you need to decrease the comb. chamber size to around 58.5 cubic cent. on an lm7 with a 3cc dish
this can be done by milling or head gasket, the best being a combo of the two.

take .030 off the head and drop to a .040 gasket and thatll get you close to 10.4:1 with a good quench

someone check me if my math is off

 

Yea. Just use stock Felpro replacement gaskets (got 2 shipped to my door for like 40 bucks) and mill them .050". It will bump you up damn near a point in your compression ratio and with that cam, you wont have any ptov issues. Dont forget you will need to buy new head bolts as they are torque to yeild.

02sierraZ71_5.3- I have .045 milled off of mine with a stock gasket and its right at 10.4:1. So i guess if you figure stock gasket thickness is .055" or so, you should be in the right ball park. It would be cheaper to just mill it more and use stock head gaskets.

 

damn guys...this is great info. what about my push rods? prolly have to call up someone and find out?
keep it coming...

Brian