69volunteer 84 Report post Posted April 30, 2018 From an EXTERNAL APPEARANCE ONLY, what would be the difference between a stock 302 and a stroked 347 (or 331 for that matter)? Seems like the only differences would be internal--rotating assembly. Bottom line, could I put the two on stands side by side and not tell the difference without taking them apart? Quote Share this post Link to post Share on other sites
Ridge Runner 1,112 Report post Posted April 30, 2018 You would have to open it up ,if the bottoms of the cylinder skirts have a notch in each cylinder ,you probably have a 347 ,the cylinder bottoms have to be notched so the rods will clear Quote Share this post Link to post Share on other sites
aslanefe 333 Report post Posted May 1, 2018 Can't you measure the stroke through spark plug hole by rotating the crank with a piece of straight something resting on the piston? Quote Share this post Link to post Share on other sites
69volunteer 84 Report post Posted May 1, 2018 2 hours ago, Ridge Runner said: You would have to open it up ,if the bottoms of the cylinder skirts have a notch in each cylinder ,you probably have a 347 ,the cylinder bottoms have to be notched so the rods will clear Thought so Ridge. I’ve seen after market pistons with shorter skirts for these stroker motors. Seems like I read you have to shave the bottom of the bores as well. I was just curious if there would be any tell tale signs from the outside. Quote Share this post Link to post Share on other sites
69ShelbyGT350H 61 Report post Posted May 1, 2018 1 hour ago, aslanefe said: Can't you measure the stroke through spark plug hole by rotating the crank with a piece of straight something resting on the piston? That should work if you can pull a plug and put something in. The stock 302 has a piston travel of 3.0" stroke, the 351w has a 3.5" stroke. The 327 has 3.25"stroke and the 342 has 3.400 stroke. Stock 351w or stroker? Cant tell from the outside. View my build photo album by clicking on the image Quote Share this post Link to post Share on other sites
Ridge Runner 1,112 Report post Posted May 1, 2018 1 hour ago, 69volunteer said: Thought so Ridge. I’ve seen after market pistons with shorter skirts for these stroker motors. Seems like I read you have to shave the bottom of the bores as well. I was just curious if there would be any tell tale signs from the outside. You actually only notch for rod clearance ,there is a small factory notch were you would have to open it up for the longer stroke rod to clear ,everytglhing else clears Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted May 1, 2018 2 hours ago, 69volunteer said: I was just curious if there would be any tell tale signs from the outside. Just curious, why do you want to know this? Quote Share this post Link to post Share on other sites
69volunteer 84 Report post Posted May 1, 2018 Looking at a car being sold as a 347 stroker. Wondering if there were tell tale signs by just looking at it. I like the idea of something down the spark plug hole when piston is at BDC...not sure seller would go for that. I guess the best way to tell would be the kick in the seat of the pants when on the gas. Quote Share this post Link to post Share on other sites
69ShelbyGT350H 61 Report post Posted May 1, 2018 Would you be happy if the seat of the pants felt good, but then you got it home and checked and found it was only a 302 or 331? If the 347 is a selling point ($$), and you are ready to buy the car, I'd stop before signing anything and handing over any money and pull a plug. If the seller is against that, try walking away and see what the seller has to say. If it's not a selling point, and you'd be happy with a smaller motor, then it's up to you if you want to make the purchase. But that's just me. Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted May 1, 2018 1 hour ago, 69volunteer said: Looking at a car being sold as a 347 stroker. Wondering if there were tell tale signs by just looking at it. I like the idea of something down the spark plug hole when piston is at BDC...not sure seller would go for that. I guess the best way to tell would be the kick in the seat of the pants when on the gas. yup,measure thru the spark plug hole. one major concern is that if it has stock heads and stock intake, it would make no sense to make it a 347 which would be the first red flag to me. also, where are the receipts, did the dog eat them? also, irregardless of what it is, if it is .040 over, i wouldn't touch it so you need to see if the size is stamped on top of the pistons. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted May 1, 2018 There's another way of determining whether it is a stroker: the amount of rubber on the rear quarters and lack of tread depth on the rear tires. Oh, you can also ask for the gas receipts and mileage calculations. 1 1 69ShelbyGT350H and MAC390 reacted to this Quote Share this post Link to post Share on other sites
MN69Grande 203 Report post Posted May 2, 2018 14 hours ago, Midlife said: There's another way of determining whether it is a stroker: the amount of rubber on the rear quarters and lack of tread depth on the rear tires. Oh, you can also ask for the gas receipts and mileage calculations. +1 Though honestly between my 306 and 347 I get similar mileage if I cruise. If I race light to light then yeah... Quote Share this post Link to post Share on other sites
69volunteer 84 Report post Posted May 3, 2018 Thanks for all the responses. Good to know. Quote Share this post Link to post Share on other sites
