Originally Posted by NewBird13
...If it is in fact a truck engine what changes will need to be made to compensate?
I recently got the same block. Like Jim described...
Originally Posted by Astrowing
It probably has a two barrel intake manifold and a truck cam though, does it not?
It also had something I never heard of, lower compression pistons.
To directly answer your question, what are you trying to compensate for? Original Squarebirds used premium gas and higher compression ratios. Today, lower compression and regular gas sounds even better unless you're trying to race to the cruise. The block itself is beefier than a car block but the dimensions and crank are the same.
I am building this truck block for Penelope in Australia. He has desert conditions so I'm keeping as much aluminum as possible, 9.2:1 compression ratio, and roller cam for today's oil.
EDIT: In my estimation, the 1973 block is much better because of parts availability. But a word of caution... Mine came with a nylon timing set, and half the teeth were missing on the cam sprocket. True Roller timing sets are available everywhere for your '73 engine. I suggest you change yours ASAP. - Dave