I've got stock 454's in my '91 PowerQuest. The ser#'s are OD513449 and 450. Does anyone know if these are Mag's or std engines? Is there a resource to find info on these, ie hp, internals? Thanks Mark

According to merc, they are standard 7.4l base motors. They were sold to greg in pa in a sea ray. The check valves on the ooutdrives were leaking and were serviced.

Wow! Thanks for the info! I am the 3rd owner on this boat and was told that they were the original engines and that they were Mag's. I took the ser#'s off the breather covers which could be wrong. Is there a Ser# on the blocks I could cross check? The original owner was from PA, but this ain't a SeaRay. Hum???

does the intake look to be higher then the top of the heads where the valve cover sits or look to be lower?

scoot me a pic if you cant [email protected]..

Thanks for the offer mr Fix, but she just got put to bed for the winter yesterday. Too much trouble getting in to look at the motors til spring......Thanks tho!

If you pull a valve cover you can get the casting numbers off the heads. Getting the numbers off the block will not tell you much.
Also let us know what kind of boat, prop, outdrive, RPM and top speed. If the engine is in top condition that would give us a good idea.

also there is a tag riveted on the block from merc with the serial number on it.