Hey Rapid, are you talking about valve springs or front/rear vacuum diaphragm carb springs? I've run a vacuum gauge in the car for many years. I have about 12"-14" vacuum, warmed up/at idle, with my current motor running a comp cams XE274 cam. It cruises at around 10"-12" vacuum (current 3.91 gears at 4000rpm on highway)

I'm building a 2nd motor for long-distance highway cruising with a very low budget. 9.5:1, 2.76 rear end, no overdrive. I'm just trying to figure out if I can run the springs that came on the Edelbrock E-street 84cc heads with relatively mild cam like the XE274 or XE274HL.

I know a matched set of cam/lifter/spring would be ideal, but I don't have extra cash to buy some springs IF the ones I have will work. The cam that Edelbrock recommends with these heads is much larger than I want to run in my cruiser motor & likely too big for 2.76 rear end gears from what I hear.