V8 to Flat 6 engine swap?

ebruns1

ebruns1

Member
Quick question fellas...

I may be able to get a currently running flat 6, trans and rear. My truck has an unknown condition (doesn't look good) flathead v8 and dubious looking trans. If I was to pull the 8 would the 6 fit right on the same motor and trans mounts with no modification or do they have a whole different set up? It's a 1-ton Express chassis if that makes any difference.

I know there are people who swear by each engine and I've read some of the pros and cons of each. Just looking to see if I have a relatively painless option to get my project running.

Thanks for any input, I'm willing to look at all sides of the argument before I pull the trigger.
 
Is the flat six you may be getting out of a car or truck ? If out of a car, I'm sure the trans isn't correct. Maybe the bellhousing too.

Sal
 
Motor mounts ,radiator,and maybe some of the sheetmetal around the hood latch area are different and the wiring harness.
 
Word of warning. If the 6 is an H parts are readily available. If out is a G parts are harder to find and some aren't made at all. I rebuilt a G because the machine shop didn't know there were two different 6's in the to 40's. Had I known the headaches I was about to have I would have gone to an 8.
 
From experience, the 6 and the V8 have the same torque. I personally like the sound and look of the V8 and would stay with a good running V8. They are available reasonable too if you look around. Parts are more readily available for the V8. And as said, radiator, mounts, etc. need to be changed which equates to $$. I had a 47 with a 6 motor and had trouble getting a water pump exchange. And when I did the shaft was a half inch too long, and fan hit the radiator. Had to track down the old core and have it machined and rebuilt. That cured me. Sold the truck and did not look back. Flathead 8s forever.
 
You can make the 6 bolt in. The transmissions and motor mounts are interchangeable. The trouble is going to be in the radiator/front sheet metal area. The 6 is a lot longer than the 8 requiring hood latch sheet metal as well as air dams. Especially the one between the hood and radiator. Another problem is parts. While 6 parts are available they are harder to find as well as much more expensive. For the money and effort invested, as well as performance you will be more pleased with the 8.
 
To me its more a question if you got a cheap supply of the parts needed for the swap.
If you can get you hands on the tin and radiator and only need to do the job maybe it will be a good deal.
But if you have to source and buy all the bits and pieces i would start by taking the engine you got apart first.
If you get away with a re-ring job its probably the way to go.
The outside look says little about the mechanical condition of stuff, you may be surpriced about what you have.
 
There are provisions (holes in the inner fender panels and front cross member) to accommodate the moving of the radiator forward. Also the underside of the hood has holes to accommodate the movement of the front air deflector forward. You can extend wires from the existing harness for the 6. Block off one set of radiator inlet/outlets. Not sure about the accelerator hookup. You'd be surprised the availability of parts for the 226H.
 
The '46 front clip I put on my V8 '47 tonner panel was from a 6 cyl truck. There are double holes in the tonner's frame with everything drilled farther forward for the six. I didn't realize it at first so now my panel's radiator is way ahead of the fan. Easy distributor access.. :) Everything bolted right up no problem. I have a six in my beater '46 half ton panel sitting next to some V8 jailbar trucks so could maybe help with questions if it stops pouring rain for an hour..... I think the 4 speed ****** is the same for both six and V8, open to correction on that.
 
The 6 cyl if in good condition will be trouble free. No over heating etc. The transmission cases are different and the v8 trans will not bolt up to the 6, but if you have a 6 cyl case around the v8 gears will fit into it.
 
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