What is the best way to rebuild a 500EFI, pretty much getting all new internals, pistons, etc...... i want reliabilty much more than HP

Send it over to Mark Boos @ Performance Marine in LA.

Call the best engine builder in the world.....tell him PK told you to call. He will sit down and talk about your options and help you out.

www.gellnerengineering.com
Dean Gellner 216.398.8500
Do a search on the board, trust me, you won't regret it.

Tyler Crockett has some great rebuilds on these motors also.

WILL

Great guy as well!

How many hrs on the engine...sure you need to rebuild the whole motor? Around 200 hrs (give or take) is a good time to rebuild the upper portion of the engine, but don't have to replace all the internals until later (500 or so hrs?). Might save you some cash just to do the upper half. As to what company you should use for new pistons, valves, etc., I will leave that to someone who has a little more experience.

I recommend Dave Govados @ MDG Performance in MD. 410-956-5381. I believe he even has a couple in stock ready to go.

just curious are you rebuilding the engine(s) in the fountain or the mystique?

The rings are low tension GM- Use sealed power standard tension metric rings

No need to replace pistons unless defective

Check Rods

Hone block to ring spec

New rod & ring bearings

New Crane long Travel lifters

Check Deck & Heads for flat

New Cometic head gaskets

New Comp 929 Srings set 1880

Valve job

New 30 PSI oil bypass valve.

Inspect all parts

Let someone familar with marine engines do the job.

He already has a builder.