Originally Posted by cobalt327
Just use the light springs for testing- the idea is to see if the engine actually wants to run w/a ton of advance or if it will detonate under heavy throttle/heavy load below 3000 rpm or so- which is the normal "all in by" rpm. Using the light springs, once you see if the engine detonates under load or not you can decide whether to use some mechanical advance or not.
To run a big cam/locked advance you really need a loose torque converter- is yours actually stalling at 3000 rpm or more? Steeper rear gears will help w/this as well. With a too tight TC and/or highway gears, detonation is more likely w/locked timing. Whether the 3.73s and the TC you have is enough or not remains to be seen.
Ideally for a car as heavy as yours is you'd put a smaller cam in the engine along w/using the correct compression to match the cam, but if you're bound to keep the cam, you should go w/more gear and stall. Gutting 600 lbs. would help, too. I've seen estimates of 4000-4200 lbs for a 1990 Caprice.
I definitely was gonna go with a bigger gear 4:30 to be exact....I think the converter is stalling right at 3000..im also mixing premium(93) with 110 race fuel so I should be able to get away with more advance