The great thing about the SBF is that it has a front-mount distributor, so there's no issue with the firewall clearance on the 240's tricky engine bay. The only Chevy swap that it is "better" than is the older SBC. Any LSx will be better than a SBF or SBC hands-down. Plus, the great thing about the LSx is that it has coilpacks.
Honestly, I've looked deeply into every swap that you can put into the 240. If you want a v8 and want good power, I'd get a 4.8l or 5.3l truck motor out of a 99+ Chevrolet pickup truck. LS1 heads and cam and intake manifold on that (LS1 guys upgrade, and you can find their parts for pretty cheap usually), and full exhaust, and you're making 300whp with at least that in tq. Now, granted, that's an iron block, but they're only about 65 lbs heavier than an LS1. And the price is more than worth it. For a trans, you can run pretty much any automatic, or an older 5 speed out of, say, a 3rd gen camaro. I would do either of those and save up for a T56 in the mean-time. Nasty car on a budget. You just either need some fab skills, or know someone who does. Otherwise, the engine crossmember mods and headers and such will add up. You'll have to either fab those or get them from HSC or something like that.
Now, since I'm sure you're more than dead-set on the 302, what headers are you planning on running? Most people just run the stock passenger side manifold, but the driver's side becomes an issue with the steering rack. It's possible to flip the manifold so that the collector points forward and up and run a U-bend, but that's pretty ghetto. haha.
Also, and forgive me if you already mentioned this, but are you planning on running EFI or a carb?