trans_am_31

iTrader: (51)

I had my heads get milled at about .065 because the person at the shop understood .020 instead of just a slight mill to just clean it up or two thousands of an inch or so. The heads were already milled at about .040 or so, so that puts them at a total of around .065.

Anyway can this heads be still usable? Can I use a GM MLS gasket so it can put me at around .056? Perhaps a thicker gasket of maybe .072 so it can put me at .46 if there is even such a gasket?

And if I can get away with using this heads, can I install a small cam or use some Harland Sharp rockers with 1.8 ratio? My heads have 2.055 and 1.60 valves and springs that are rated at .0625, I dont know if this info helps.

Any help is welcome, I feel sad as this was a great misunderstanding on the part of the shop and my heads are now highly milled.

Ericbigmac83

iTrader: (19)

What heads are these? The safest answer is to clay the heads and find out. Sounds like you're gonna be fly cutting if you wanna do a bigger cam though.

GR33N GoblinM6

iTrader: (14)

.065 of a mill???? wow...

yeah what heads were these to begin with? because the basic math for LS1 heads is you take .007 off for 1cc off the combustion chamber..

lets say you have 241 heads... they are stock at 67cc's... a .065 mill would take a little over 9cc's off... putting you at 58 cc's

if these were 806 casting heads.. they are 69cc's stock... would take you to 60 cc's

if they were 243 LS6 heads.. they are 64cc's would put you at 55 cc's..

trans_am_31

iTrader: (51)

Gentleman, I really appreciate your feedback. These are the 853 castings 5.7 LS1. I understand that if I am to put a cam it would be rather small somewhere in the 525-550 lift range.

Do any of you think I may be better off just using the Harland Sharp 1.8 Rockers by themselves.

I am trying to find a thicker gasket to help offset some of the milling. What do you guys think would be best.

GR33N GoblinM6

iTrader: (14)

well its not just the lift per-say.. its the duration too.. i would stick with the 1.7 rockers... what are your goals for compression? because with this combo you are already in the 11+ compression

853 heads were 67ccs'.. so you're now at 58cc's...

best thing to do, call up a few engine builders (Texas-speed, LME, ect) and tell them what you are working with, and what you are going to do with the engine. They also will advise you on what pushrod length you will need as well.

eamador11

i agree

trans_am_31

iTrader: (51)

I guess if I buy .072 gaskets I can maybe help offset about .020 off of the head leaving it perhaps at .045 !

Do you guys think I can be safe with the 1.8 ratio Harland Sharp Rockers?

Any suggestions are appreciated.

PREDATOR-Z

A .065 mill will definately create intake allignment issues.
Yes you can run a thicker gasket, BUT then you increase your detonation chances and this could result in high KR and loss of power.

since the shop made the mistake, I think they should swallow the pill and provide you with a new set equal to what you had in the bigining (a stand up shop would at least)

good Luck, sorry for your issue, that is FU

BIG_MIKE2005

iTrader: (116)

^^Listen to this guy. He knows his **** & helped me outta a very tight spot on my heads situation also. He told me everything I needed to know, did the calculations for my SCR & DCR since I don't know how to do those correctly & pointed me in the right direction. It saved me from runnin heads milled to much which would have caused me to only be able to run race gas or constantly detonate.

From what I know I wouldn't even try to use those heads. Thats flirtin with disaster.