Projects 1949 GMC 1 Ton engine swap or rebuild

I had the '51 version of that truck back in the 70s. It had a lift gate on it and the best rear springs I've ever seen on a small truck. I think a 9' bed as best as I can remember. The original 17" tires, 7.50 are about 35" tall and make 55-60 highway speed feasible. There was also a 8.25 tire available but I don't think they are made now.

I was building a house with a big fireplace and needed fill brick for the core structure and went to a local concrete brick maker. Brick size,not blocks. I went to the office and asked for 1000, two pallets loaded on my GMC. The guy first refused then agreed, but didn't like it. When I drove back up front to pay, he couldn't believe it wasn't draggin' the rear bumper, just dead level at about 2.5 tons. Wouldn't want to drive far or over 45 but it was fine for the 6 miles I was going. 85 lbs of air in the tires and that spring pack I mentioned earlier.

It also had the 228. Ran great and handle loads with ease. When I got it there was a dead miss on one cylinder. Pulled the plug and there was no gap. Regapped and put it back. Still missing. Pulled plug again. No gap. Took a look inside. Piston was backwards!! The dome was closing the plug gap! Pulled pan, removed rod cap, turned piston around and reinstalled cap. Ran fine. The previous owner had installed rings, rod bearings and did a valve job. Couldn't get it to run right.

 

My 49 gmc cane with a 235.
It was removed due to a knocking sound. The previous owner didn’t know the gmc had insert bearings.
A couple of 270s and 248s have come up recently but dang the rebuild cost.

 

I'd go along with the concept that a new set of rings, a new set of bearings and gaskets and a valve job would have that truck ready to run another 50 or 60K without much of an issue.
Not every engine absolutely has to have a complete rebuild job with new oversize pistons, cam, lifters an all the other pieces.

A vacuum gauge will probably tell you if the valve guides are worn excessively.

Unless you are just bent on doing an engine swap I don't see where that is going to save you any money over a ring and valve job right now.

 

I should have said engine bellhousing pattern, thanks for the correction to what I meant. The trans bellhousing pattern could be confused with the pattern where the trans bolts to the bellhousing.
I also forgot about the 261 Chevy engines as part of the 216/235/261 engines family.

Sent from dumb operator on a smart phone

 

It sounds like the concensus is a new set of rings, a new set of bearings and gaskets and a valve job. I think that might be in my budget. New glass, lots of body work, paint, new bed wood, tires, rims, etc. I'll be $4000 more into this if I do all the work myself. I just might do it. I've never had to rebuild an engine before, even a partial rebuild like you've described. Any advice on how to make the job easier? Potential pitfalls?
Oh yeah...here's a couple pictures of the driveline.

 

Open drive line. Cool.
You could swap in a rear with better gears.

 

That overhaul is not difficult. Locate a service manual. Take lots of disassembly pics. Mark and tag all the wiring. Bag the bolts and bits.
A friend familiar with measuring would be great. Or locate a machine shop you trust. Explain the results you want. Like said before. Not every engine needs a total rebuild.
if you take it apart, some pieces need extra attention. The lifters need to go back on the cam lobes they came off of. Number and mark them so they can be returned.
A wise man told me the best time to build an engine is before it fails.

 

@anthony myrick .....I agree with your comments....but it really shouldn’t be necessary to remove the lifters to do an in frame ‘overhaul’. In a pro shop I hung around as an adolescent, that was a common ‘done in a day’ job. Head off and to the machine shop, cut the cylinder ridge out with the reamer, drop the pan, push the rods/pistons up and out. Clean up the pistons and decarbon the ring grooves, hone the cylinders and reassemble.

They typically did not change the main bearing shells, babbitt Chevys might get rebuilt rods, insert models, new bearing shells. Bolt it back together and go. Not a sloppy job, just an economical overhaul to stretch the engine life for thousands more miles.

Not suggesting the OP should expect, or be expected, to do a ‘one day wonder’. Only pointing out it doesn’t have to be complicated to be effective. The enemy is the “while I’m in here, I might as well.......”. Resist that unless something is absolutely needed.

Ray

 

The only reason I mentioned the cam and lifters is this. That’s an old engine. Just about every engine I tear down is full of sludge.
I had a great 352 that I should have pulled and at least cleaned it up, and reseal. The pushrods stopped up and killed the rocker arms and bent a valve.

 

Excellent point. I was forgetting that the engines I spoke of were typically five to ten years old, not seventy!

Ray

 

Dang non detergent Quaker state

 

I had someone give me a reasonable offer yesterday, so, this one is getting sold.

 

I'd love to see how one of the current crop of late model plastic buckets would cope with rear ending that old girl when the driver is texting.

 

Funny. We had that very conversation during the sale!

 

the survival rate of the occupant in the newer car is higher
the survival rate of the vehicle would depend on which old car it rearends
a pewar car would not would not preform as well as the new "plastic bucket"
a 70s era big bumpered land barge would probably do well

 

Personally I don't care about the texting driver in the plastic shopping trolley but I bet the truck will drive away whilst the late model would be a total. Texting drivers should be charged with dangerous driving potentially causing death.