Four Bolt Main
 

How would I know what I was looking at if I were looking for a four bolt main? Also, did all 1970 boss 302's come with a four bolt main?

If you're looking for a sbf, the 302 boss is the only factory offered 4bolt. It will have screw in freeze plugs. Ford didn't do the huge number of 4bolts that GM did. Other 4bolts would include late 351C's including the Boss,CJ,HO and 4Vs, 429CJ's and SCJ's, 406 and 427 (little different route though) and 4.6 SOHC's. DOHC's are 6bolt. The pushrod 4bolts have another common characteristic, MONEY. They ain't cheap. You could also opt for a A4 or R4.

hey you forgot my 428 cj with bolts from the top and the side to definately hold those caps down...