compression with 317's and mls?
 

I have a stock bottom ls6. I want to put the 317 heads I have on to lower compresiion abit while I build my 6.0 block. how big (thick) can I go with a mls gasket. I know I cant get the compression to low with head gaskets. but with 317's and a thicker head gasket how low can I get it. I would like to get down to 9.2:1 if its possible.

thanks

i have used a couple of different compression calculators and some show 9.6 and some show 9.8. how much boost do you plan on running?

http://www.race-cars.net/calculators...alculator.html

I would like to run 7-8 daily, then like 12 or so with pump/meth at the track. maybe crank it up a bit more if I ever get it running on e85.

you'll be safe, thats safe boost with a good tune. ive had mine to 16 on the stock block with 317 heads and 3 layer mls. wont last much longer but owell

i run 12-13psi daily on mine on pump gas and no meth. i am using 6.0 gm mls gaskets.

what is the compressed thickness you guys are running?

.053 part number 12589227.

I shouldn't have to change my push rods, right? I'm not sure how think the ls1 gasket is.

what valve springs are you using? i used prc's so i changed to tsp push rods.

Ls6 springs,ls6 cam. Set-up made 550 when I had a sts. Not sure what pushrods are in it. I bought the car with the sts. Sold that and built my own front mount.

prolly 7.40

so i shouldnt have to change them then? what if i put ls7 lifters in, since mine have about 100k on them.

You run a 6.0 MLS gasket for a 317 head on an LS1 right? I have a set of 317's I wanna slap on too.

yup, 12589227

Thanks.:cheers:

Same setup here.

I've run 15psi in 100+temps with just an a2a no meth setup. You should have no probs with what you plan to do.

Looks like a couple of us got info we needed lol. I plan on putting a set of 317's on here in the next couple weeks, run 12psi and hopefully run meth...thanks for the part numbers guys..deff made stuff easier...also hope I dont blow it up lol

thats good to hear, temps are 100 + in tucson at night lol. so I should be good for what I want to do.

only thing left to figure out is if ls7 lifters are taller then ls1 lifters. if there the same I dont have to get different pushrods.

i hear the cup sits .05 higher than the ls1 lifter.