worth it to bore a 302 to a 331? how much would it cost and how much difference would it make?

 

In my opinion if you are thinking of boring to 331, do a 347. The oversize bore is the same +.030. The stroker kits are about the same in price. I spent about $900 on my Probe 347 kit. (steel crank and forged pistons and rods). There is no replacement for displacement and a SBF is no different. The 347 is a great build. I love mine. Go for it!

 

Actually the 347 does have its drawbacks over a 331. Such as thickness of the pistons. And it is even worse if you are trying to get low compression out of a 347, that takes more material away from the piston. In a power adder situation for anything other than strip only I would stick with a 331. I am running a 331 with 8.2:1 compression and 17-18 lbs of boost on the street pump gas.

 

Correct. I had a 347 awhile back and it was great but if you plan on using nitrous or other power adder in the end you would probably be better off with a 331 - small yet mighty (Just my opinion though). More guys end up blowning up 347s - especially with the power adders they are ok for everyday use = I see alot more of them going into the older F-150 as a replacement for the 302 rather than a mustang. A friend of mine has a 331 right now with a 88 mm turbo and it is the perfect balance of engine size vs Rpm.

 

+1 94IVGT and Rumblin 6
347 naturally aspirated
331 power adder
choose one based on what your future plans are and build accordingly

 

depends on if you plan on building a power added motor. nitrous works great with 347. but the 331 is better for blowers super chargers or turbos. I have always built 347's the are amazing motors. this time I plan on doing a twin turbo street car, so I am working on a 331 right now. if you need any help pm me.

 

To each their own, but this has never made alot of sense to me. Why not just start with a 351W, and save the machine work money for the engine build itself? Better block, substantially beefier crankshaft, etc..