it would be difficult to get that compression with those 118 cc chambers. look for a set of alum heads with the chamber size you need.

What current casting number do you have??

There was a $2900 502 for sale this week. Prosystems carb and such.

Too bad.

Current casting # 360 peanut heads not looking very useable trashed out and tired. Bottom redone 2 yrs ago. I am freshening-up the stock engine not buying any real performance parts, read alum heads, just putting the boat to good running order for 1-2 years.
I saw the 502 and the 509 and would like to have but i need to swap the alpha for bravo before adding any "real" power.
I found some recent rebuilt 781's for $250 my head shop said they would replace valves with stainless 2.25/1.88 and cc and machine heads for compression correction for around $400. I thought this to be a prudent direction.
Am i missing something? I am asking 'cause i really am no expert at this.
Thanks and as always any all sugestions welcome.

Those 781's will blow your 360'sw out of the water and with a tad of machining they will hit your comp ratio. Do an RPM Airgap intake and go have fun. This will really wake up your engine.

It has been sugested to use inconel exhaust valves. My question is what is different about them, when are they needed and why? Thanks again

http://www.performanceboats.com/dyno...el-valves.html

If you cut the heads enough to raise the compression you will most likely have to cut the intake to match. The 2.25 valves may be a waste on that small bore motor and just cost you some low end torque. You might be better off with some closed chamber heads with 110 cc combustion chambers.

We are running the 781 heads on a 461 BBC in an all steel Chevelle and the engine is a monster! It pulls like a freight train in the eighth and will be in the 6's with some tuning....all steel and full interior I might add.

781 heads are great, with a bit of work done to em.

What compression, what gears, what cam ? what have you compared them to ?