Best upgrades for stock 502?

[Bromaguire]

What upgrades can I do to my stock carbed 502 that will show the most gains other than building the engine or a blower. Right now I have lightning headers and a msd ignition.

[YoungPerformance]

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

[jeffswav]

What upgrades can I do to my stock carbed 502 that will show the most gains other than building the engine or a blower. Right now I have lightning headers and a msd ignition.

Do you have the long risers? How many hours are on the engine? If you have long risers and low hours you could get a Roller Cam, lifter and springs from Bob RMbuilder. That was the best upgrade I have made. Of course that may lead to a intake and carb upgrade also. Don't let the speed bug get you, you will never shake it.

[Raylar]

Eddie said it perfectly!

Best Regards,
Ray @ Raylar

[Chris]

Not only is Eddie right on with the upped compression, getting correct deck height optimizes the combustion chamber's quench area. So not only do you get an increase in compression (more power) you get an increase in detonation resistance through the more efficient combustion process you get with optimum quench effect, which lets you run maybe a point or two more timing (more power).

[MILD THUNDER]

Is yours a 500HP or a 502/390HP? If its the 390hp version, a carb/intake, roller rockers, heads and roller cam will REALLY wake it up. Actually, just a cam/intake/carb will do wonders on a 390HP 502 merc especially if you already upgraded to headers.

[Geronimo36]

What upgrades can I do to my stock carbed 502 that will show the most gains other than building the engine or a blower. Right now I have lightning headers and a msd ignition.

If you're not looking to spend much I'd go with a Crane 731 (HP500 cam) or the next step up with a crane 741, Dart Single Plane, roller rockers and a Holley 850.... These upgrades would not require a total build...just the top end. If you have an extra $1600-2K handy, some aluminum heads are nice but at that point may as well do the whole engine! The cam/intake/carb will get you in the 500-530 hp range

Few years ago I had a blown engine in my Scarab from a broken oil cooler line and the cheapest route was to buy a 502HO engine, swap my Merlin heads and install a new cam. I was able to sale the GM heads for $900, the roller cam/lifters for $600 and $500 for the blown short-block and I paid around $4500 for the new long block... So basically I put a brand new package together and in the boat for $2K....and didn't miss any boating time!

Frank

[Tony M]

looking for cheap speed try blue printing the bottom and then work your other magic you wont belive what it will do for your total package.