Im almost done with my 1990 Iroc 383. I installed a new camshaft(slp 495/502lift. 218/224dur.), new cylinder heads(ProTopline Alum. 200cc/64cc), new injectors(Ford 24lb.), and a Superram. I have a brand new distributor(MSD 8366). My question is: Can I just drop in the distributor? Do i have to change the springs inside the dist.? Somebody told me that i had to change the springs inside the dist. to match the timing of the cam. But I thought you could just drop it in, set the timing and your ready to go, since it is a brand new dist. Does this make sense? Any help in clearing this up would be greatly appreciated.

 

Most MSD distributors come with a couple sets of advance weights and springs (unless it is a 7-Pin computer controlled unit, which doesn't use either anymore).

You can install it as is. All the weights and springs do is allow you to tailor your advance curve. Using lighter springs and/or weights will bring timing in sooner, which often helps power, but not always. Track or dyno testing is the only way to really be sure how this is working. Otherwise you just need a balancer with a timing tape, or one that is engraved with markes from 0-40 BTDC. You could also use a dial back timing light, but it will be a little trickier this way. Either way you'll need a tach to know where the advance is at a given RPM.