JaSSon

iTrader: (11)

Im wanting 11.1 compression with those heads and cam and Im using stock GM head gaskets. How much do I need to mill to achieve this? Im thinking .015. Can I use my stock length rods. Im also running Yella Terras, Will this affect lifter pre-load? Thanks for any info.Jason

Jabroni

Are they 5.7 heads, or 5.3 heads? You'd probably need to mill .030" on a 5.3 head to ge the CR that high. With .030 milling, exercise care with the X1 cam. There may be P/V issues with lifting that high. Clay or verify the clearance with that cam and .030 milling. Period. Some have done it without any issues and some have smacked pistons and broken valves. Check it, check it, check it.

Stock gaskets are fine. If you only want to mill .015, you can use a Fel-Pro gasket to raise the CR a bit since they are slightly thinner than stockers. You can use the stock PR's, but anytime you change the relationships in the valvetrain geometry, you need to compensate it somehow. Shimming the rockers would be the easiest because the next shorter PR is a 7.350".

How do you like your YT's? I'm contemplating a purchase.

DaleMX

iTrader: (4)

I think that stock 5.3's are about 11.3 or so already, but 5.7's would need milling to acheive that CR.

DaleMX

iTrader: (4)

Stock 5.3's have a 61cc combustion chamber yielding 11.1.

Damian

iTrader: (89)

A stock, unmilled 5.3L head will NOT yeild 11:1 right off the bat. Milling .015 will put you @ 11:1 w/ a 5.3L head.

J2KSS, w/ the X1 cam do not mill below .025 for safety. If you're running a 5.7L head, milled .025 and run an 02 Multilayer gasket(.005 thicker than standard). If you're going to run 5.3's, mill .015 and run whatever gasket you'd like...

Josh

JaSSon

iTrader: (11)

Damian, can I still use my 7.4 pushrod and preload should be good with yella terras huh?

Damian

iTrader: (89)

My TEA 1.5 5.3's are cut .020, and I am using a stock 7.40 pushrod w/ no problems. I am not familiar with the characteristics of the YT's, so I cannot speak on that...

josh

verbs

My stock 5.3's came out to 10.8:1.

blk~2000~Z28

Make sure to check clearances if you do mill just to be on the safe side.
Attached are 2 posts about a problem someone had that was supposed to be an OK setup as far as clearances are concerned.

https://ls1tech.com/forums/generation-iii-internal-engine/111243-p2v-clearance-mti-stage2-ls6-x1.html
https://ls1tech.com/forums/generation-iii-internal-engine/114365-mti-stage-2-ls6-x1-clearance-problems-pro-s-inside-please.html

Brian Tooley Racing

iTrader: (13)

The 5.3 chamber untouched is 59cc but is undesireable due to its 3.800 bore, our CNC ported 5.3 chamber is 63-64 cc depending on which exhaust valve is used. You have to mill a head about .006"-.007" to remove 1cc worth of material.