1970 c10 350 4 bolt main?
 

New to me truck about 4 months ago. On the tail end of a restoration
I don't see myself pullinf the oil pan anytime soon and trying to find out if my 350 is 4 bolt main.
Being work Trucks where they all 4 bolt?
Just curious.
Thanks
Mark

Re: 1970 c10 350 4 bolt main?
 

My 70 C20 is a 4 bolt main. Original engine, rebuilt once

Re: 1970 c10 350 4 bolt main?
 

Look for the casting number on the top of the block BEHIND the left head, right next to the firewall. If the number ends in 0010, then, yes, it's a 4-bolt main.

If you want to rebuild, then do it. We just went with a 350 crate engine from Radley Motors in VA. MUCH cheaper than trying to rebuild.

Do a search here for Radley and look it up that way.

Re: 1970 c10 350 4 bolt main?
 

Not all the 010 blocks were 4 bolts.
327's could be 010 blocks and where definetly not 4 bolt.
You need the suffix code from the front pad to know for sure

Re: 1970 c10 350 4 bolt main?
 

Even then that is not positive. The only way to tell positively is to visually see the main caps, which of course means pulling the pan

Re: 1970 c10 350 4 bolt main?
 

I agree with this...

Re: 1970 c10 350 4 bolt main?
 

And unless you're wanting to brag to someone who doesn't really know the difference it's not going to matter. Until you get into the 400+ hp range the 2 bolt is perfectly adequate. And if you're going to really build a motor, you probably want splayed main bolts.

I've been inside a lot of motors, and I've never seen a main bearing cap fail in a stock motor, 2 or 4 bolt. The rods are likely to go long before the mains do.

Re: 1970 c10 350 4 bolt main?
 

Fully agree.
To my understanding they put both 2 bolt and 4 bolt blocks in the trucks.

One interesting piece of info that I received years ago....was that the 4 bolt main engines were easily identified by a 1/8" Npt plug, facing upwards at a minor angle, in the front casting of the block....just below the intake manifold join and just left (passenger side) off centre close to the upper water pump area.
Supposedly this was used to either pre-lubricate or test something connected with that 4 bolt option. (?)
I don't know if that is fact....but the truck engines that I have seen that are 4 bolt, have had that 1/8" npt plug.

All Good
Coley

Re: 1970 c10 350 4 bolt main?
 

Interesting tidbit, hafta check that out