Re: 302C to 351
your thoughts are correct.
its as simple as getting a 351 crank, some 351 rods and using them.
there are options how ever! you can also use the 302 rods with some application specific pistons.
The closed chamber heads on 302's will giv you a high CR. Make sure your block or head hasn't be decked to much and your CR should be ok for BP Ult.
I used 22cc dished pistons and shaved my heads 20thou for a CR of about 9.6:1. I wouldn't advise this.
Go stand 351 crank and rods, stnd 302 cc heads and use BP Ult. You will need hardened seats for this to work long term.
you have asked in the right place! if seomone else hasn't given you the run down before I get home, I can help out as I have just done this in the last 6 mnths.
still have cheap places where I ended up going,
one thing about my job, phone calls to anywhere are free, so when i shop around, I SHOP AROUND EVERYWHERE!