Visual difference in 302 vs 347?

I came across a really good deal today on a complete car. Body is pretty much gone. (floor pans, battery case, hood, cowl the usuals) The main reason I bought it was because of the v8 engine that was in it. It sounds very good, headers, racing distributor/radiator the works. Only thing is though, the previous owner didn't know if it was a 302, or a 347. Is there any visual differences right off-hand that I could go by to tell the difference? Other than taking it apart.

 

All of the parts that stroke a 302 into a 347 will only be internal. My 393 Cleveland externally looks no different than before I took it to the speed shop as a 351

 

If he built the car he'd know.

 

That's the thing. He did not build the car. He got it in on a trade. He's not a Ford person, lol. Just trades a lot. Ahh, okay. What shall I look for Mav 1970?

 

A 347 has a 3.400" stroke, 302 has a 3.000" stroke. Pull a spark plug, move that piston to TDC, stick a coat hanger wire in the plug hole and and mark where it enters the hole. Move the piston to BDC and mark where the wire enters the hole. Pull the wire out and measure the distance between the marks.

 

First try what Barry suggested with the coat hanger to measure stroke - other than that you would have to pull a head to measure the additional stoke and the larger bore, then do the math

 

would it have the...351 firing order...

 

Any 302 can get that with a cam swap.

 

Go into it figuring you would be getting a 302 and price it accordingly. If he's bent to get more hoping it's a 347 make him prove it.

 

X 2 Only don't expect to come up with those exact figures in measuring due to the angles involved with the spark plug holes and the wire moving while you're rotating the crank. It would help to measure a "known" 302 first and see how the measurements fall into place before measuring his.

 

Awesome replies! Thanks everyone. One of the most friendly and informative forums on the internet. Loading it up and bringing it home after work today.

 

you said you bought the car what did you pay for it?
if it runs good and has a decent exhaust system on it worst case is you bought a parts car with a good running 302 figure a decent running motor and trans are easily worth $500 and an exhaust system you like is another $200 then any other parts are on the car you can use or sell say another $300 so I would say as long as you didnt pay more than $1000 you did good if it turns out the motor is just a 302 but if it turns out to be a 347 you did very well

 

I gave $300 and a Marlin .22 rifle for it. Edelbrock low rise intake, Edelbrock 4bbl carb, mesh breather, headers, bucket seats, small bumpers, early model grille with a perfect round medallion, aluminum sport wheels, 3-speed trans, high-performance electronic distributor, heavy-duty aluminum racing radiator and an electric fan.

 

302 or 347, you did OK. A brand new Marlin .22, is cheaper than the carb alone.

 

If it has stock heads there's a 99.9% it's a 302, rarely will anyone build a 347 and not upgrade the heads...

Still sounds like you did good...