How do the factory exhaust manifolds differ from one another on the 502 mpi and the 525 efi engines? Can they be interchanged?

No. The 525 comes with headers on a different bolt pattern. 502 mpi is reg manifolds on standard bbc bolt pattern

NO, the 525 has Edelbrock alum heads and a non standard exhaust bolt pattern, the 502 has a standard BBC bolt pattern


haha typing at the same time

Thanks guys. I am building a manifold set-up and was hoping I could cater it to both engines, but I will have to do 2 I suppose! Are they both the same angle heads? Could I simply swap the cylinder head flange to make it work on both?

Are you building headers, dont really understand the Q

Somewhat, yes. I was wondering if I build them based on the 502 if they could also be used on a 525 efi. Now that I know they are different, would a flange swap be all that is required to make that happen?

yep, if you change the flange to match the 525 bolt pattern

Easy enough! Thanks!!

just a side note, the bottom 4 holes will line up, its the upper four that wont, beleive me I know, I redrilled my CMI GenX to fit my AFR heads,

I'll have to get a pair of each in hand to check them out. I wonder if the flange was drilled for BOTH if any issues would result or if this would allow them to work on both!?