Mill the 317's .020" and use a .040" cometic gasket.

 

Hey Klug,
How did you calculate the DCR based on the cam specs the OP listed? To me (and I haven't the brain for this), it looks like you would need more specs. I'm not doubting you, I'm curious because my setup is very similar and I've been going off of a friends calculations/experience.

My setup:

'03 LQ9 (31K miles, FWIW)
LS6 intake- mildly hand-ported, mostly to match TB adapter
80mm TB
Z06 243s
EPS 226/230, .598/.600, 113+2
1.75" long tubes
FLT Level6 4L60E
2002 S10 extended cab (3300lbs.?)

My friend spec'ed me a slightly different cam- 228/230, .571/.573, 112LSA, 110ICL. On my LQ9 with 243s, he calculated 11.13SCR, with that cam- 8.43DCR. 228 isn't one of EPS's options, so I went with the 226. With the larger lift and advanced timing, I don't believe my DCR will change much from what I was spec'ed, will it? I'm not trying to hijack the OP's thread. I figure if mine was determined to be ok, then the OP's should definitely be ok since his is slightly less aggressive than mine.

 

Sure no problem. I've got a pretty slick DCR calculator/spreadsheet that I use that is Excel based and it is accurate. Also I am very familiar with that cam he is running so I have all of the full specs on it. My DCR spreadsheet has a pretty big list of Comp specs and lobe numbers for many lobes out there. It's pretty handy! I can do some figuring the long way too on calculating DCR but with that handy spreadsheet it has spoiled me! LOL.

 

I plan on putting in a LQ9 with 243 heads. I got the heads for decent price and my LQ9 was a short block so it made sense to pick up 243s.

 

Well scrap that whole plan for now. My buddy I was getting the short block from truck ate a cam bearing. So we swapped the flat top motor in last week with a set of cleaned up 241's and a tsp 224r. Runs good.

 

Finally found this thread again! I'm subscribing this time.

So, Klug, can you tell me what my DCR would be with those build specs I listed?

 

Cometics are too expensive in my opinion. If you're having the heads milled, take an extra .010-.020" off and run stock gaskets.

 

Don't fear compression. If I was going back n/a I'd be running 14:1 compression on E85.