Other than the obvious............horsepower. Does anyone one know the exact internal differences between 502mag mpi, the 500 efi, and a 525 efi?
I am assuming it is mostly in the heads, cam and ECU but since I'm tearing down my 502mag to rebuild it, was wondering what the internal differences are and if it would be worth trying to duplicate vs. building say a 540 or putting a whipple on it.

Thanks for the input.

The bottom ends are all the same. heads on the 502 MAG and 500 are the same. The efi525 went to edelbrock heads. All 3 of course have different cams.

anyone know the actual specs on the different cams?

500 efi has the same bottom enf as the 502,the 500 efi i believe has a crane 731 cam, the 525 efi has a differant upper intake plenum that flows more cfm,the bottom end has k5 h beam connecting rods with a crame 741 cam..the blue engines are soppose to be blueprinted engines compared to the black engines.

If you are looking for more HP, I would look here http://www.offshoreonly.com/forums/d...e-results.htmland try to copy the build.
That is about as much HP as you are going to get out of a 502mpi without an intake manifold change and major modifications..

502 Mag
224/224 .478/.478
115LSA

500 EFI
230/236 .598/.610
114LSA

525 EFI
236/244 .610/.632
114 LSA

Thanks for the info guys!

HP500 has inconel exhaust valves and stainless steel intakes, whereas the 502 Magnum has stainless steel valves both sides.

MC

My 500 efi had Manley h beams with Mercury Racing etched on the side when Potter tore it down.

HP500 has a different intake than the 502 Mag MPI.