302 to 351 swap questions

On The Edge Fabrication

Well-Known Member
Looking to add some displacement to our truck....currently we are running a stock 302 and want to gain some displacement and power.

Which parts are interchangeable? intake, heads, cam, brackets for accessories??? would a 347 be better than a 351? How about getting the 351 stroked?

What about the physical size difference between the 302 block and the 351

Thanks any advise is greatly appreciated


Well-Known Member
351W has about 1.5" taller deck height making the whole motor an inch 1.5" taller and wider. Heads are interchangeable. Acc brackets are not. Cams are interchangeable but there are 2 different firing orders. Just make sure your plug wires are routed correctly for the cam you have.

351 blocks have bigger main bearings on the crank.

347's have kinda crappy rod ratio's.

I personally like the 3.750 stroke cranks as the rod ratio doesn't get out of hand.


partybarge_pilot mentioned the width... so it should be obvious but don't forget this added width means it requires a 351w specific intake manifold. Head bolt openings on some 302 heads will need to be opened up for use on a 351w. The exhaust may require a partial re-do because the deck height is taller on the 351w. Depending on engine cage tube placement this may or may not be a problem. Your down pipes from the headers may require lengthening. Distributor might need some attention too if you are going to transfer it from the 302 to the 351w. The oil pump hex sizing changes at a certain year and you need to make sure the oil pump drive shaft is the correct length. The thing to watch out for is width... the 351w is wider than the 302 and if you aren't careful you might get to a certain point during the swap where you realize the added width requires removal / modification of existing cage work.