Mercury Racing 525 replacement style heads.  Three intake runner sizes offer potential for increased levels of performance.

We’ve retooled Dart’s PRO1 BBC castings to produce a true bolt on upgrade for the Mercury Racing 525 engine. The PRO1 24° 525 MMR is available with 310cc, 325cc or 345cc intake runners and has the correct exhaust bolt pattern for the factory manifolds. A grey chromate surface treatment inhibits salt corrosion for marine usage.

Heads are sold individually.