What he said!

That particular casting number denote a 350 cubic inch cheby... could be either 2 bolt main or a 4 bolt main. From your other posting showing the deck numbers, if I remember correctly, (my Hollander manual is not at home) CCl was a truck suffix, so I'm guessing it is a 4 bolt main. As far as to what them heads are, the best way to tell is to pull the valve covers and find the casting numbers. Then just do a web search for "Chev casting numbers"-- you'll find so much info there that your head will swim.