Hi guys, wondered if you would know if these heads would fit an 87 merc 454 mag engine, mine are in need of a fair amount of work so these would be easier and cheaper but only if they would work well.

What might be the pro's and con's of fitting these?

http://cgi.ebay.co.uk/CHEVROLET-BIG-...item2308f4f970

They look ok. Oval ports are good for a 454 as long as they are not peanut heads. Ask him for the casting numbers and then look them up and see what thy actually are. And you realize those valves will need to be changed to severe duty ones or they won't last long.

Those heads are also closed chambers. Normal heads on a Mercruiser are OPEN chambers.

The chambers on those are really small, it will bump up your compression. Also those are small valves, you can have larger ones cut.

all you will get is alot of torwue with those heads,,with the small valves in them your power range will be all over @ 4200 rpm..find somthing else..

Good upgrade head for 454

http://www.jegs.com/i/World-Products...96#moreDetails

Great info guys, think I will stick with reconditioning mine.