Swapping X's for Trick Flows

Mopar69gts said
Hi there,
Thank you for your response.
We'll originally I had installed the cam dot to dot.
Regrettably I did not degree it.
So I really don't know exactly where it is.
It seemed a bit lazy on bottom end and only had 10" of vacuum with 20* initial timing
So I moved the timing set to the 4* degree crank advance key way.
It picked up some bottom end and vacuum went up to 12"
Cranking compression also went from 165 to 170+
After playing with the distributor, carb, pcv valves...etc vacuum came up to 14
The x heads have been milled to 66cc
Running 91 I could only put 32* total before it would start pinging.
If I need to I'll put the cam back to where it was.
I'm also hoping having some quench .044
Will help it some too...

OK, so you found the limit of timing on the X-heads. That's what you have to do.... I did similarly with a 10.3 SCR/8.3 DCR iron headed engine with quench on 93 octane.

If your X-heads were at 66 cc's then you are only going up about 0.5-0.6 points on the SCR/DCR, not a full point. With that, the AL plus some quench/squish effect plus the small chambers will make up for than much and a bit more IMHO. So you have a good chance to be better off.

BTW, I get around 8.5 for DCR.

I think I'd time the cam if you can and push the cam timing back a couple of degrees. You're gonna pick up some low RPM torque with the added SCR/DCR.