will these fit big blocks? looks tight but is it possible? new to the site so thanks in advance!

You need 33 inches between engine centers to do that. Unlikely they spaced them that wide.

If they won't fit rebuild the small blocks to supercharged. Lighter than big blocks, cheaper than a bore and stroke, and fast. Or if you are into it, maybe do LS motors. Bet you can get some chine walk.

do twin ls motors lq4's, ls3/l92 top ends make a easy and "cheap" 500 hp that will live for ever

You wouldn't want BBC's... too heavy in a 24... in the 27 they are too heavy. Sbc's or ls for twins, really the single 502 boats handle and ride very well and will do 60...

I have an 84 272 I'm thinking of swapping because of cost the center to center on my 272 is 33.25 inches

Redneck has 3 bb's
1 in his boat, most of the time
1 at the machine shop, always
1spare in his garage, when he doesn't have 2 at the machine shop.
Sorry, Hunter could not resist

I like the above idea of twin ls engines. I dont see twin big blocks fitting. I hate to work on a single in mine. I cant imagine 2 of them. Also as stated. I'd bet the swim platform would be under water. Sum***** would look like a hydrostream vector with an optimax on it.