71 340 Compression Test

for 340-4bbls
All the heads were pretty much the same, as were the A/T-cams. The power differences were in the pistons, and the carbs, and the tune.But more than anything was the rating system. The 72 engines were pretty much the same as the 71s, with just carbs and timing. The 71s were rated 275 and the 72s were rated 245,IIRC. Same engine but with retarded timing and new rating.
In 73 the compression was dropped and the engine was downrated to 240, go figure.
I'm going from memory so corrections welcome

The 71 TQs were factory rated275, but NHRA wasn't fooled and rated them 290
The 6 bbls were rated up to or factored 325hp.
the long blocks on both were the same.

The factory 4bbl intakes are all pretty much the same
The exhaust manifolds are a mess, but headers are a must to make the cams work properly.