Right now I have a stock carbed 502 with lightning headers and msd ignition. What are the best upgrades that I will see real gains from other than building the engine?

Which verson of the 502 do you have? The older 502/390HP with the quadrajet carb or the 502/500HP?

If the older version, I would suggest a cam upgrade, roller rockers, intake and carb. With the right combo of cam, intake, and holley 800 carb, 500-525HP should not be a problem, especially if you go to a hydraulic roller cam, like a crane 731 or 741.

get rid of the circulation water pump and go with a crosser-over set up.thats worth 10 hp there.cheap and easy

It may be the older one I'm not sure exactly which generation it is. My mechanic told me it 415hp though. What cam and intake combo would be best to get me towards 500hp? Will my stock bravo 1 like 500hp?

Do you have a picture of what your talking about?

whats the deal with eliminating the cir pump and just running a cross over?? Pro's and Cons' and is there anything else you must do???

If its carbed, then its 390 hp. The 502mpi is 415hp.

Real gains????? Figure that you need 15HP to gain 1mph on the top end. The most you are going to gain without going into the engine is a couple mph. If you do engine mods, you'll need better exhaust for 2k or so. Best bang for the buck is a prop lab job. Changing to a crossover is not worth the 7-8 hp IMO.

With the addition of some aluminum heads(and a little more compression) and a camshaft, you could easily make over 600 hp. This will be the best bang for the buck. You could get a good set of aluminum heads(complete) with quality parts for a little over 3K. In order to get all of the compression that you could run, you would have to surface the block, since the pistons are quite a bit down in the hole. Just by surfacing the heads and running a thinner head gasket, you could get the compression to around 9.4-9.5:1. This would be enough to get you over 600 hp. Hope this helps.
Eddie

Mercruiser also made a T-465 hp carb version 502. they were made from 1990 to 1992 and were also called the 502 magnum..



P>S> listen to eddie..

The real question is how much do you want to spend??? How many hours on the engine???? Define "without building the engine." There is little to be gained without going inside it or at least adding a supercharger.

Disregard the "needing better exhaust". I reread and saw you have Lightning headers. Those should be fine for a cam upgrade.

Same story here - been thinking NA 540 built for torq for a while since I would like more HP and torq but need reliable and I dont know how hard one can push a 502 (even with higher compression and better flow). Seems like the short block costs for a 502 or a 540 or a 555 are almost the same these days