Pat
I called Crocket and Precision Marine they were very reluctant to give me any information about their cam spect .they said that its better then the stock 500 EFI. ,and compatable with a silent choice system. Crockets price is $375.00 and Percisions is $325.00. Both will be able to reprogram my ECM to match what i have already installed, and i will be able to use the stock lifters.

Well, I'm sure that Crockett and Precision have developed their own custom grinds and EFI calibration to match. I think they have 600+HP upgrades too.

From your posts, it did not sound like you had purchased and installed a new cam yet. What cam did you install?

By the way, lots of people have run the Crane 731 (same lift as a Merc 500EFI) with the stock GM lifters. When I install the 500EFI cam I have sitting on the shelf, I'll be checking out if the stock GM lifters will work; they are about half the price.

Bob
I did not purchase a cam yet I am still in the research mod.Crocket and Precision did tell me that their cams are a
custom grind, and i can reuse my stock lifter. I went on line to Crane Cams and look up #731 its not a Crane number.

It sound like you should buy the cam and ecu recal from the same source then...

731 is not the complete part number, it's just what everyone seems to call it.

Good luck with your project.

You have not mentioned re-programing your ECU and in my opinion this will be a must. I went to merlin heads with simular valves, bigger injectors and a mag cam. Lots of changes and the ECU took 6 hours to re program in the boat. Best money I ever spent. Fuel delivery should also be looked at. Tyler @ Crocket Marine does the re-programming and coould advise on the fuel delivery.