For some of you Merc repair shops...
The Mercury Racing 525 has been out for a few years now and are out of warranty. This being the case I am starting to get a few customers with this engine asking about freshening the heads. While reading all the mass hysteria in the racing and general discussion forums concerning the DQ of a SuperV Fountain, I noticed a statement in there about Mercury Racing never planes or decks their heads, they are always replaced. Do I need to tell my customers that the Merc Racing 525 heads can not be resurfaced? If this is indeed true, and Merc Racing replaces all 525 heads, what happens to all those old heads? Can they be bought somewhere? If a certified shop pulls the head for whatever reason under warranty, and the head surface had any minor imperfection, did Merc Racing warranty the head?
If they were still using the 525 in Factory racing, I'm thinkin that would make a factory rebuild close to $10k. Ouch!

you cant surface them for class racing. if the customer is not a racer surface em and do a valve job.

If it's ok for the average customer, but not the racers?
What does Merc Racing do with the heads that come off of the race motors? Can they be bought as used heads?

surfacing the heads raises the compression and along with that HP slightly too. in spec class racing that would be an advantage over the guy running them right out of the box. not sure what they do with all the take off's.

Stupid rule. The other point in this kind of class with factory motors is to keep racing affordable. Having to buy 2 sets of aluminum heads when a simple resurface will do the job doesn't make sence. Sbi allows it.

I thought the 525 heads were Alum Edelbrock's ??????


Surfacing a head .005-.010 will not make if any HP .Unless ya really cut them and zero the deck,thin head gasket etc

Most heads that need resurfacing dont need much takeing off.


Being a closed cooling systen the heads aught to be in real good shape!!!!

I have 1 new in the box 525 head, not in love with it willing to sell or trade.

They are Edelbrock heads marked up 1000%.

This is true but have better parts, comp guide plates, ARP studs. think comp springs and retainers.

Has odd Ex bolt pattern.

Would post pics if i could figure it out.

Be careful where you buy new heads. I believe Merc heads for the 525 have a special exhaust bolt pattern.