Hi All tring to figure out what type of SB heads I have..

They have a "Double Hump" casting.
Right under the double hump GM 24t
H28-78

Casting is Either 954434 or 354434 cant read the first number.

Just wondering if the heads are any good...

Thanks

Off a '75/'76, 262" motor. They have little-bitty, 1.72"/1.38" valves!!

Too small for a bigger motor.

Post the letters at the end of the VIN number string on either the deck pad above the pass. side water pump top bolt or on a little round pad above the top middle of the water pump pulley and hopefully we can tell you what motor you have if it is still stock?

pdq67

Freebird,
I just picked up a pair of 291 double hump that came with int 1.95 ex 1.50 valves for $150 at a junk yard. You may want to go that route if it is double humps you are after.

Late 70's 2bbl 305's used the 434 castings also. 63cc chambers, 1.72/1.50 valve's. Even with a decent cam they run out of breath on a 305 by 4500 rpms...BTDT.