Thread: OBSESSED HELP ME! I cannot tell what engine I have.

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A 390 is 4.05 bore, 3.78 stroke. That seems to be what you have, yours could be overbored at a rebuild in the past. As for your intake not fitting "right", that's a common thing with FE's. There are so many critical measurements it's easy for a manufacturer to screw up a little on one of them. Most common I've seen is the valve cover surfaces not at the same level as the one on the heads. Usually doesn't matter much, just use silicone for a gasket.

You say the bore is between 4 and 4 1/4? How close to 4 1/4???? a 427 is 4.23, just under that. If that's what you have, boy, that's a keeper!

Time to buy a new tape measure if the closest you could figure was somewhere between 4 and 4.25. (or maybe your eyes are like mine )

Don

Thanks much fellas. I know it is know the bore is not at 4.23, that would be nice but just not my luck. Any ideas on a quality crate engine source?

Originally Posted by R Pope

You say the bore is between 4 and 4 1/4? How close to 4 1/4???? a 427 is 4.23, just under that. If that's what you have, boy, that's a keeper!

That one would be easy to spot with it's cross bolted main caps