Hi, I got a 2 door hardtop 64 Buick Lesabre, original and all complete. Currently it still has the original Buick 300 with the one year only aluminum heads and intake while serviceable components are available for that engine parts parts like heads or intake are impossible to find and being that this was the one year only design only complicates things further so what I’m wondering is because this motor is sat since about 1984 and is currently seized and very little performance parts are available. What would be a good idea for an engine swap I thought about a Buick 455 But those are hard to find a good running motor for now, so I’m almost wondering to what about a big block Chevy or a something along those lines? Ideally carbureted and something that makes good power. I think the 300 was underpowered for a car that heavy. I don’t want to blisteringly quick thing and I don’t wanna mess with an LS swap with that rats nest of wiring. something that would’ve been realistically available in the 70s or 80s but I also don’t want to destructively modify the car to the point where if I wanted to swap the 300 back I can still do that. The platform is a GM B body, which would’ve been the same as a 64 impala. Feel like a small block Chevy is just too ordinary I deal with those all the time, A more interesting engine that realistically I could still pick up a good one for cheap
I would look for a 401-425 Buick nailhead and the 400 turbo. I understand that the later Buick 350 is a decent option too.
What is end goal? Nice cruiser or more performance? Always easiest to get a complete running donor car if doing a swap. Most likely a smaller V8 like Olds 307 or 350 can be found in some 80s sedan that runs good and body or interior have seen better days. Remove the emissions junk you don't need, and the swap is not any more difficult than if you found a 60s donor car.
Easy button, Buick 350? 3.800" bore has some folk turn their nose up at it, but that also gives you lots of piston choices. And if you ever want to stroke the 300 for more torque, that Buick 350 crank will come in handy. 307 Olds is plentiful and made 140hp/180hp net depending on cam(stock), and are smooooooooth runners. But you would still have to deal with engine swap issues such as accessory brackets and the rewiring/plumbing to make those work.
As far as this engine swap goes I’m looking to have a little bit more power than the 300 (210 hp with 2 barrel ) would’ve put out from the factory doesn’t make much sense to swap in a less powerful engine the olds 307 has been mentioned in the thread a couple times. What’s the hype about those motors? Also, with a Buick 350 would the mounts be interchangeable? Also, it sounds like as far as transmissions goes my best bet sounds like a turbo 400.
The Buick 350 is an underappreciated engine. It was used in the big cars and moved them along just fine. If you could fine one with either turbo transmission, I think that would be an easy swap.
Olds 307 only because it was used up to 1990 in the GM family, and would be more likely to find. Not a bad engine, and you could install that and look for a bigger Olds (ex: 350, 403 or 455) which would be simple R&R later with the bigger engines being slightly taller and wider (increased deck height). The 307 would be combined with an OD trans, probably the 200-4R. OD trans would be a nice addition with your engine swap. Buick 350 is a good engine, and I'm pretty sure the mounts are different than your early Buick 300. Just harder to find since Buick V8 faded out of production in 1981. Be a little harder to find a complete donor car. Same story with Pontiac, good engines but production ended late 70s.
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