Engine swap on 65 GMC 2500 305 V6
 

We have a customer truck here that has a 305E engine. It has two dead cylinders with piston and cylinder wall damage. I purchased an engine from a wrecking yard that was listed as a 305. When it arrived, I checked the numbers on the right side of the block and it is a 351. I realize that the timing cover, possibly the oil pan and intake may have to be swapped. It appears those gaskets are the same on both engines. Is there anything else on this swap that will cause a problem? Will the flywheel, clutch etc all bolt on?

Thanks

Re: Engine swap on 65 GMC 2500 305 V6
 

Pursellauto:
Which 351 is it? Could be a 351c or 351e. In either case, flywheel and clutch will be okay. Reason I ask is that 351c is small port engine vs 351e is a large port magnum engine. 351c can use 305 manifolds. 351e manifolds are different.

Hope that helps.
Regards
Steve
New Orleans

Re: Engine swap on 65 GMC 2500 305 V6
 

The stamping numbers on the right front of the block say 351 only, no letter after that. The used engine came with intake and exhaust manifolds attached. The carb on the 351 appears to have a governor mounted under the carb. I am making another assumption that we can use that carb minus the governor to fuel the 351.

Re: Engine swap on 65 GMC 2500 305 V6
 

Couple of pictures of the motor would help. Magnum has trapezoid carburetor base, for instance. Non magnum carburetor base is symmetrical.
Regards
Steve

Re: Engine swap on 65 GMC 2500 305 V6
 

Both carbs have the same base, 4 studs from manifold in rectangular shape. We are thinking about using shorter studs from 305 to the 351 and bolting the 351 carb directly to manifold eliminating the governor.

I am trying to upload .jpg photos from my computer but getting a message that PNG file has the incorrect file extension.

Re: Engine swap on 65 GMC 2500 305 V6
 

Attached are the two carb bases for magnum and non magnum. The magnum trapezoid base is marked 60053 in the picture. If you have the manifolds for the 351, then the carburetor might be the only thing that wouldn't swap from 305 to your 351 without an adapter plate.

Hope that helps.
Regards
Steve
New Orleans.

Re: Engine swap on 65 GMC 2500 305 V6
 

Both carbs have the pattern of the gasket on the right side as looking at the picture.

Re: Engine swap on 65 GMC 2500 305 V6
 

You are in luck. Everything other than pistons and crank should interchange. Your 351 should be the small port version, typically a 351c.
Regards
Steve
New Orleans

Re: Engine swap on 65 GMC 2500 305 V6
 

Thank you, Steve for your assistance.

Re: Engine swap on 65 GMC 2500 305 V6
 

Pursellauto:
You are welcome. Post some pics when you get it running.
Regards
Steve
New Orleans