To tell if your engine is a 2 bolt main or a 4 bolt main. Turn the engine upside down on an engine stand. Next, count the number of bolts on each main bearing cap. if there are two, then its a 2 bolt main. And if there are4, then its a 4 bolt main. This applies to the three center caps. The front and rear are always 2 bolt.
4 bolt main
The difference between a 2 bolt main and 4 bolt main is how many bolts hold the caps that hold on the crankshaft. (A 2 bolt main has 2 bolts to every cap and the 4 bolt main has 4 bolts to every cap) A 2 bolt main should be able to handle 500hp as long as you don't push it above 5500RPMs.
1500--2 bolt, 2500 4 bolt
305 sbc 2 bolt main
no cause a 4 bolt main has 2 extra bolts on each main
i have a engine with this # and its a 2 bolt main
You could check the block serial number at mortec.com, but it's probably 4 bolt.
If its a 1/2 ton it will be a 2- bolt main, You can run the engine # if you need to know for sure. But i'd bet its a 2-bolt
If it's the factory engine, then it will be a 2-bolt main engine.
can be both ,i have a 350 010 2bolt main
it is more than likely a two bolt main. i have a 90 1500 and it was a 2 bolt before i changed motors