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ricric

10-29-2009 07:25 AM

merc 502 head rebuild

ok, if i have stock 502(415hp) heads rebuilt,port/polished and rollers installed (if nt already stock,not sure) what extra hp can i expect and do i need to reprogram ecm?? I already have the stainless marine ex manifolds installed.who in chicago area can do this work reliable/fair pricing.

Young Performance

10-29-2009 07:29 AM

I assume you have a 502 Mag. Yes, you will need to do some programming with that much head work, especially the porting. In order to take advantage of the port work, you should change the camshaft. With that, you could pick up 30-40 hp, possibly 50. I don't know anyone in that area that can program a Mefi. I can and I'm only about 8 hrs from you. Hope this helps.
Eddie

corbvette

11-04-2009 03:56 PM

Who did your head work?

JimV	11-06-2009 02:17 AM

Who did your head work?

That would be my first question too. What valve size and what airflow gain?

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