Mthd11

Can you bore out a 302 to a 331, or is a 306 the most you can go on a 302 block? Im assuming you have to get a new block and a stroker kit for the 331 correct? and by a new block i mean a 331 block. could you slap on a 302 lower/upper intake and have it fuel injected or is it carb only? do they make fuel injection for the 331?

By the looks of it 331's make a hell of a lotta hp. but you dont see alot of them, is it because theyre less reliable or 347s and 351s are just more popular and bigger lol.. go on streetfire and search 331, they look and sound pretty badass...

frop

331s are only strokers in a stock block. 347s are what's hot, & 16 more c.i. Almost any SB Ford combo can be carbed or FI in any number of ways. 331s don't have a specific block, it's a standard 302 block.

gspfunk

302=4.000" bore x 3.00" stroke (stock 5.0)
306=4.030" bore x 3.00" stroke (bored over .030"--helps clean up cylinder walls on a rebuild)
331=4.030" bore x 3.25" stroke (327 if bore is stock)
347=4.030" bore x 3.40" stroke (342 if bore is stock)

The 331 has a rod ratio close to that of a 302, making it more reliable. The 347 has a smaller rod ratio which tends to make it a shorter lived motor. That doesn't mean it's going to blow at 10k, just that they don't usually last as long as a 302 or 331.

If you have a 5.0, you would use your stock setup for whichever motor. You might need to upgrade injectors and some other things, but you'd retain your stock wiring, computer, etc.

Mthd11

for some reason 331's appeal more to me than the 347s and 351's the videos on street fire make me drool...

and boring it out to 331 wouldnt bring it to close to the water jackets?

edit: i found a good article on a 331 build. http://www.mustangandfords.com/techarticles/5197/

gspfunk

No, it's only bored over .030...just don't go more than that on a stock block

tinman

Don't worry about the rod ratio/lenght thing and just build the 347..
I concur about not ever trying to bore the stock block past .030...