is there a way from the casting numbers on the front of a block to tell if its a four bolt main

 

No, the same castings were used to make 2 bolt and 4 bolt blocks. Only the finishing machining was different.

If it's a 305, there's almost no chance that it's a 4 bolt block.

 

no i bought a 350 yesterday i know my305 isnt one

 

For pretty much anything streetable, it isn't going to make a difference to you whether it's 2 bolt or 4 bolt. If you've got the engine already, then there are only a few oil pan bolts keeping you from finding out either way.

 

true i didnt think of that but i cant do it its sitting on a crate and i dont have a stand

 

well depends on year.
the 305 outta my truck was a 4 bolt. 83 GMC K1500

 

Yes, 4 bolt 305s do exist, mostly in Canadian pickups. Not especially common, though.

 

well my 305 was an 85 lg4

 

interesting...ive always been told they didnt come from the the factory as 4 bolts, you had to splay it out.

iono why everyone desires a 4 bolt over a 2 bolt, especially in a street car. how many motors have you personally seen that have **** themselves because you didnt have a 4 bolt main cap...granted im only 19 but ive been around engines my whole life, my dads built them for 30 years and my grandad (first person to get the SBC to break 10,000 rpms in the outlaw sprint series) has NEVER seen one fail because of this, just fail because of dumbass builders..

but to answer the question, if you look the casting number up most likely you will get "some were 4 bolt, some were 2" im with Apeiron just pull of the oil pan...

 

to be honest with you a 2-bolt 350 can handle 400+hp anyway. it'll handle anything you will most likely throw at it.

 

id like to know the casting number off the block of this supposed 4 bolt 305

the stamping cod eis whats on the front pad of the blocks btw

alot of the times the listing will say if its 4 bolt or not by the stamping code




good luck

 

I have heard of 4-bolt 305s in trucks before, though I have never seen one.