reliability is the KEY for me here. I am just making a some what respectable street car...If I built a 347 it would be in a mexican block with something like 351W heads or GT40 heads...with a mild cam...If I go 351W..I might use an aluminum head to reduce weight here and again a mild cam....Not trying to wind the crap out of the thing....OR I might just stick with my original HiPo 289 that came with the car, but the HiPo is NOT going to perform NEAR to the level as a 347 or a 351W....

 

How does it offer more power? They will both accept the same heads and cam, the stroke is nearly identical, the bore is identical. Where does the power come from? Once you eliminate the 351Ws intake issue there isnt much difference.

Maybe if you are considering a worked over 347 and a stock 351 then sure, more power in the 347. But assuming the same mods to both engines, they will make similar power.

What matters is what fits. Are you allowed legally to swap in a 351? Will a 351 fit in the chassis? What do you have as a starting point, as in what do you have now, do you already have an engine or will you be buying a complete one?

With the 351W you get a taller block with larger head bolts and rod bolts. Longer rods and the capacity for more cubes with stroking. Its a more robust engine than the 289/302 and will fit almost any Ford chassis. It is heaver and the stock intakes arent very good.

With the 347 you get a shorter engine in a lighter package that will fit in any Ford rwd chassis, and could concievable pass a visual smog inspection, its still a 302 block. The cubes are maxed out so no more stroking and with the .060 overbore, no rebuilds either. When buying a stroker or kit the quaility of the parts is very important. Also clearancing of the block and balancing of the reciprocating assembly. Then its a matter of what flywheel/flexplate and balancer you need.

EFI is available for both engines, same with aftermarket heads, cams, intakes, exhaust, etc, etc, etc. Either will work just as well and the only real difference is what you already have and what its going in.

 

Well I don't have either and they will be going into a 66 GT fastback....
If it is a 347 then it WILL BE Mexican block.
If it is a 351W IT WILL BE a 1969 or 1970 351W block.

 

if you are looking for reliable i would go with the 347, you want power, go with the 351, but mod it. you can push a 351 to 800 easy with the right mods, but you sac gas mileage. if you go the 347 route, your mileage will be a bit better but you will not have a high powered car. really it falls down to what you want power or performance.

and thumpin, a 351 will fit into the first gens bay, but with work. stock exhaust mani's gotta go and depending on the type of headders used, you may have to massage the towers. like i said, it comes down to what you really want and have time and money for.

 

The 351w will make more torque based on the rotating assembly. Pick up a 302 crank vs a 351 and you will see why. Definetly more enertia from the weight of the 351 crank. HP will be close but the 351 always make a hair more. I have driven both a 347and a 351w Both shared identical parts, other than the intake was for a windsor and not a 302. Both were running rpm intakes and in identicle 65 coupes. The windsor was faster hands down.

 

I voted windsor. Were you talkin whp or at the crank?
-P.

 

Yeah I am sort of leaning towards windsor. it seems windors is just a better built motor...I am looking for around 350 hp and very low end torque around 2500 to 3500 RPM rang...I need to be able to drive this to work...or more a less WANT to drive this to work if I choose to...So I sort of want good gas mileage....but what do I do with the HiPo 289?