'74 Glastron, two engines, where do I start?


New Member
I have a '74 Glastron with 350 hours on it. It was powered by a 302, 200 hp V-8 ford, Volvo 270 drive. I bought it new and we used to live on a lake hence the few hours.

Anyway, it was stored for over ten years and now I am revitalizing it. In storage two freeze plugs had popped out. I thought I had thoroughly drained it. I put in a battery and it wouldn't budge.

I thought the engine was frozen up and with a bad bit of troubleshooting I concluded that something was locked up in the engine. It was the starter, though, I found out after pulling out the engine. :eek: In the meantime I had bought a new crate mid 90's Explorer Long block which would give me roller tappets and GT40 heads.

I rounded up some OMC EFI components and thought I would put together an EFI Explorer 302 engine.

Then I found the old 302 was in pretty good shape with hardly a ridge in the cylinders. It's weaknesses were that it was an older engine, it had a Glastron. One of its weaknesses is that it has a log style exhaust manifold with "Glastron" embossed in the casting. Nobody seems to know much about it and gaskets seem impossible to get, that is gaskets beyond the ford head bolt-up manifold.

In the meantime I decided that the EFI is too complicated to retrofit (I put them on Ebay, if anyone is interested." Now, I wonder whether I should stick in the later Explorer engine or go back to the original. I think I could get a few more horsepower out of the Explorer plus have an newer engine.

So, here I sit, wondering which way to go. Rebuild the older engine or go to the newer one. :brickwall:

Ideas, anyone? Here is your chance to throw in your two cents.



Staff member
It sounds like a fun project - wish I could help more.

Maybe some of the I/O guys will chime in and have an opinion or two.

I hope you'll post up some update pics as your progress, it would be fun to watch things come together. :)



New Member
About the Boat:

Oh, about the boat. I found the picture of the Glastron. Not bad for a '74 boat. Engine is in foreground, also work bench before top was added. I am still having my challenges working with this website.

By the way, does anyone know anything about a '74, log style exhaust manifold that has 'Glastron' cast in it? I am wondering about gaskets on the backside before it connects into the Volvo outdrive pipes.

I will try to keep posted on progress.




Active Member
you would still have to change the head gaskets over to marine ones in the new engine and i would make sure that the fuel pump port on the side of the new block is not cast over as well. you should be able to buy aftermarket manifolds and risers for the volvo set-up.