C8-H heads were very common heads to find on FE's. The intake is a truck part with the TE in the number but have been found on pass car engines. Look for a "T" on the intake. The heads have a date code between the 2 center valve springs under the VC. You can see if they match the block. You can measure the stroke easily.... put the #1 on TDC and remove the #1 and 4 plugs. Insert a wood dowel or stiff wire into #1 and mark using a common edge as a guide. Then insert into #4 and mark again using the same edge as a guide. Measure the distance between.
3.50" is a 352 stroke crank
3.78" or roughly 3 3/4" is a 390 stroke crank
3.98" or roughly 4" is a 428 stroke crank.

The only thing left to guess is the cyl bore. To confirm you'd need to remove a head to measure the bore. But I think Henry nailed it as a 390. A 428 would be a nice surprise tho....

G.