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2873 Views 33 Replies 7 Participants Last post by  rbay
Hello Everyone,

New to this forum. Posed this question to the Minnesota Glastron Carlson forum, looking for any and all input from all of you:

I recently purchased a 1973 Glastron Carlson CV21 to restore....I think I can keep the interior and exterior pretty close to original. It has a newer Berkeley jet pump, but no engine. Two paths engine replacement could take and stay the same 320 hp range at about the same engine "ready to drop in" cost are:
1.) Build and install an early 70's vintage Olds 455 big block like original. I'm pretty certain I would use a Holly Sniper EFI fuel system and an HEI distributor, but otherwise pretty old school. Would integrate into the boat's electrical system, gauges, etc. like the original. It came with Olds 455 logs/snails, water pump plate, and bellhousing. Servicing it would be a project for the owner/mechanic or hot rod shop.
2.) Install a used early 2000's Mercruiser small block, like the 350 MAG. Would have modern ignition and EFI. It would take about $400 worth of wiring, switches, and alarms to integrate it into the original dash and controls. I don't know how easy it will be to connect the bellhousing engine mounts to the pump. Any Mercruiser service center could service it for me or any new owners.

So when thinking about reliability, driveability, sensory, fun, resale, servicing, what would be your vote? I know fuel economy will favor the newer engine, but Michigan summers are pretty short and I don't get to put that many hours on my boats, so that takes a backseat to the other factors. Or am I missing some things to consider? I know there are higher powered options, but 50-55mph is fast enough for me, wife, and puppy to cruise around the local lake. Key to me is confidence we will get back to the ramp without a tow.

Thanks for you thoughts.....option 1 or 2? I know there are a lot of car guys trying to make this same old vs new motor decision on their classic rides, too.
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As mentioned above, go woth a big block. Jet pumps eat torque. You want as much as you can get, and it isn't coming from a 350 without serious investment. Being that you have access to a bbc, that would be the path I would take. But don't discount an Olds. 455's were installed in thousands upon thousands of jets from the factories for a reason. They run reliably and make mounds of torque out of the box. They just have limitations if you are looking to run your boat really hard.
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