Okay, so I have a 67 with a 350 in it. Im planning some new mods for the future. I am trying to find out where I can find if my block is a 2 bolt main or a 4 bolt main. I have looked all over the block(What I can see of it with it in the car.) to find out. Any suggestions?

 

There is one way to find out but it's a hard one. I don't know if any numbers on the block will answer this question.

 

I dont really want to pull the motor and tear it down just to figure it out seeing how it will be a while before I get to work on it again like I have been lately.

 

Not sure why you want to know if it a 2-4 bolt mains. There is really no difference untill your making over 500HP. Simple mods if your leaving the motor in the car are a Comp. EX-268 cam and a set of vortec heads. This will put you right around 400HP at the crank and you won't need to upgrade the stock converter. Easy bolt and go.

 

I thought about eventually running a supercharger and swap the two speed powerglide to a 4 speed manual. The supercharger is why I want to know if its a 2 or 4 bolt. Its just a thought. I am perfectly happy with my tunnel ram 350(no stall).

 

I would cross those bridges when they need be.

 

Camaro Decoding help on Chevy-Camaro.com

 

Is the 350 from 67? If it is not and you not sure what it is before you run into the 4 bolt main issue your going to want to know if it has a Cast iron crank or a Steel crank. If you don't know what the bottom end is like don't do anything to it. You could have a cast low compression pistons and cast crank. Nothing in that motor would hold up well under real pressure. That old cast stuff can be ok but if there are any casting defects your going to find them the hard way.

Your going to have to pull the motor to see what you got. Even if you track down the block you have no idea what someone put in there. Its a 67, it takes what? 3 hours to pull the motor and you should not have to set your beer down. Heck even if it was a 4 bolt with a steel crank I would want to replace the crap GM rod bolts before doing anything to the motor. You have to have a strong base to build a decent small blocks. These are not LT1 or LS1 motors. If it is a 1975 350 the block is about the only usable part on the motor.

 

And there you go.

 

If you're going this route, take it from another "blue suiter".... Go LSx POWER! You can find a nice used L92/LQ9/LS2, etc...engine/tranny/computer/gas pedal for around 3K. Check out Pro-touring.com and LS1tech.com.. work on building that up! You will not regret it.