You're gonna need a dizzy anyway
And this board isn't the best for giving unbiased info so here's my .02 cent
Do not build a 347 they have oil blow by badly, just go a tad smaller
If you're going to build a motor build a 351 stock motor and spray the Jesus out of it
Reason you ask?? Cuz it's gonna be cheaper than all the ignition crap you'll have to buy for your ls motor. Yes an ls motor will handle a shit ton of power but if you have a budget a 351 will in the end be cheaper (900$ for a used fast intake for ls motor)
If you go after market rotating assembly it's 1200 heads 1300 bolts 500 that's all arp motor bolts gaskets 200 ish then intake and carb prolly 6 to 800$ depending on deals or used, used can be dirt cheap
That is all for basically my motor which is a 408 ci and I run high 10's on motor no spray nothing. It's in a notch so it's somewhat light.
It seems to me and the more I read that ever since I was in high school people build sbc for dirt cheap. I know they are or were cheaper (haven't looked in a while) but when doing an engine swap I would not use one unless I knew what car I was gonna use due to the dizzy being in the rear of the motor and I just don't like the idea of having to pound the firewall or use a wheel barrel for a trans tunnel ( joke on jokes) just so a very important part won't arc or hit
So in conclusion don't build a 302 if you want power above 450ish
Don't build a 347 anyway
351 but I am biased
Ls motors can be got cheap but it's when you start modding them is when it's pricy
Sbc can be very cheap
If you want ls then buy a 5.3 truck motor and wiring and ECM for like 500$ and put head studs in it and spray the Jesus out of it that would be the cheapest and quickest and prolly fastest way Just don't mod it that's when it gets more expensive than a sbf
Sorry for absolutely no punctuation but I can't find my keyboard for my ipad