Hard to say, you've added weight but also gained a little comp. Question is does your combo need more CFM airflow from the heads. Could probably benefit from a little more.

Your combo is running pretty good for its 3820#,s The RPM might be a little choke up top , but the spacer does give it a little more cushion. But with your 252* cam and 4000 stall vert @ 3820# you Want that RPM intake, choking or not. Its whats helping you move that car below its torque peak which is around 4500 with that cam.

Its going to be faster for sure, but only by maybe a tenth or two at most IMO... With your car being so heavy, I think advancing the cam to around 104/105 ICL would help too, verses being straight up on a 109 icl.

Nice combo.