Originally Posted by vinniekq2
hei stock is great to 5,000 RPM,after that it needs help. 1 5/8 primaries are great for low to moderate power,750 DP is a good carb. should be a tire melter. what shape are the valve springs in?
The HEI is the Procomp, I know not the best, but it has not missed a lick, even at 6800 rpm, 1.5/8 headers i know are a bit small for the 406, The springs are like new, there doubles with pressures at 132 seat, 320 at .500 lift., It IS a tire fryer no doubt, just doesn't put down the ETs i think it should, my main concern was the cam (510) not perf. well, Its like I'm wondering if its a flow in the positioning of the key when it was built, I just lined up the dots on the little cam & it runs pretty good, pulls 16 inches vacuum (in gear). The 510 only got about 6 inches when i'm sure it should have been around 9-10.