I came across an automatic 1981 Regal coupe with a very tired v6 and a decent body that would make a nice project. Car has an unusual interior too, w/ tan rugs and offwhite/eggshell corduroy like upholstery. I've never seen much other than grey, maroon or blue for a Regal interior. This would make exterior color change easy. Car currently is an ugly sandstone tan! I also have a friend that has a 1965 300 ci engine available that has already been rebuilt (cheap). Is that a possible swap with the existing trans/motor mounts? Seems like a fresh mid 60's small block would put out enough HP to move out a relatively light Regal body better than a smogged 307 Olds?
I currently have a 65 LeSabre conv that has a 4bbl 300 that moves out ok. Anybody ever try this?

I never did this but I thought about it. If it were me I'd opt for finding a decent 69-70 Buick 350 motor. Just about every other person who has one of these cars is throwing the 350 away for a 455 lately. That 350 might be better suited to lighting up the rear end on that Regal.
Plus I understand the Buick V6 is the 350 minus two cylinders. So this should be a basic drop in engine.

Or you could also opt for a sweet Buick 400 or the 430 from a 67-69, but you'd have to take a look at the front springs to beef them up with that much weight.

JD

Not familiar with swaps and such, but if you want to put in the 300, make sure its the high performance version. Buick made 2 300 engines, the high performance is the 11:1 piston ratio. Mine is all original in a Skylark with the 2 speed tranny and posi rear end--she has eaten a few 350s for lunch. Not the fastest thing off the line but punch it at 40 and its bye bye. If that little screamer had a trans with more gears???? It is fun to say the least.

I do have a 4 BBL Wildcat 355 in my 65 LeSabre. It moves 4,000 Lbs of Buick convertible around just fine. That's what gave me the idea. A friend of mine has a 2 bbl Wildcat 310 in excellent shape to bolt right in. It doesn't need a rebuild either for $200. I would think the 65 small block has more hp with 9.5 compression than a smog era 307, it can't weigh more than the Olds either? Slap a 4bbl intake on the 300 (I can get one locally) with a free flow exhaust and you would have a fun car to drive. Question is, will it bolt up etc?

I think it would go right in there. The bellhousing will bolt up and the accessories may also fit right on there. I just wonder about the oilpan though, the 65 Lesabre may have the center sump, you may need the rear sump pan.
CTX-SLPR was thinking of doing something similar- he had found a '8* regal manual transmission car for a posssible swap.