MY6 250 6 cylinder Swap to LS Gen 3 and TKX

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shawn57nomad

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Hello all,

So here's the short term plan with our 81 C10 Custom Deluxe with a stock 250 and factory MY6 NP833 overdrive 4 speed. LS swap an '05 Gen 3 6.0 from a donor G3500 van and add a Tremec TKX 5 speed manual with the close ratio setup. We'll follow this with new driveshaft and a 9" housing with a helical traction device holding 3.50 gears.

This is an absolute bare bones truck with 0 options. It's going to be a cruiser with a/c and later cruise control. We've purchased mounts and a such through Tejas SteelWorks. The engine should be forward a few inches and will prevent notching of the frame rail on the passenger side and allow for the truck accessory drive and components to be used.

Here's my concern(s). Will the TKX fit in place of the MY6? Planning on SFI bell housing right away to add a Wuhan War Whistle later. I don't want to cut the high hump if possible. Also, will the mid shifter conversion be necessary if the power train is moved forward?

Any help or thoughts are greatly appreciated. Thank you in advance.
 

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TotalyHucked

TotalyHucked

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Welcome! Like Rick said, I've got a sorta similar setup to what you're planning. I've got the Tejas Steelworks engine mounts, trans mount and their 13" dual electric fan shroud as well with Spal fans.

I have a gen3/4 bastard child 5.3 with a T56 Magnum from Tremec and the T56 wouldn't fit under the stock low hump floor. I can't say 100% but I'd be willing to bet you'll at least need to massage the tunnel to clear the top of that trans. I cut mine out and bolted the high hump in that we make (I work at AMD). The high hump is overkill, but it's a whole lot easier to do that than to try to massage the floor.

For the shifter, you would most likely need to do the midshift conversion to hit the stock hole. But again, if it won't clear the floor, it's not really a concern. My shifter worked great in the rear most position, but the seat had to be all the way back or I couldn't get in 2/4/6th. I wanted other people to be able to drive it too so I flipped the shifter to the front setting of the rear mount and it's still great.

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shawn57nomad

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That looks really good! Thank you both for the input. I'll definitely post results with pictures when I get the swap installed.
 
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MOTORTRASH67

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shawn57nomad said:
Hello all,

So here's the short term plan with our 81 C10 Custom Deluxe with a stock 250 and factory MY6 NP833 overdrive 4 speed. LS swap an '05 Gen 3 6.0 from a donor G3500 van and add a Tremec TKX 5 speed manual with the close ratio setup. We'll follow this with new driveshaft and a 9" housing with a helical traction device holding 3.50 gears.

This is an absolute bare bones truck with 0 options. It's going to be a cruiser with a/c and later cruise control. We've purchased mounts and a such through Tejas SteelWorks. The engine should be forward a few inches and will prevent notching of the frame rail on the passenger side and allow for the truck accessory drive and components to be used.

Here's my concern(s). Will the TKX fit in place of the MY6? Planning on SFI bell housing right away to add a Wuhan War Whistle later. I don't want to cut the high hump if possible. Also, will the mid shifter conversion be necessary if the power train is moved forward?

Any help or thoughts are greatly appreciated. Thank you in advance.
Click to expand...
@shawn57nomad Hey! I don't have any info to help, but I am curious what your plan is with the old MY6 Trans is? I have a 67 Belair that I'm installing that same RPO Code transmission in, and unfortunately, I'm missing a TON of parts for mine. I just did a "rebuild" on my transmission, but I'm missing everything from case hardware to the shifter and shifter linkages. If you're looking to let go of it or some of it, I'd be interested to know what you'd want for it! Thanks!
 
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shawn57nomad

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Engine Size
250
MOTORTRASH67 said:
@shawn57nomad Hey! I don't have any info to help, but I am curious what your plan is with the old MY6 Trans is? I have a 67 Belair that I'm installing that same RPO Code transmission in, and unfortunately, I'm missing a TON of parts for mine. I just did a "rebuild" on my transmission, but I'm missing everything from case hardware to the shifter and shifter linkages. If you're looking to let go of it or some of it, I'd be interested to know what you'd want for it! Thanks!
Click to expand...
I'm not quite sure but undoubtedly there will be a 250 attached to it when I get it removed. I'll keep you posted on the MY6.
 
mcarlo86

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Did you get the 250 and transmission pulled?
 
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Scruffy49

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shawn57nomad said:
Here's a little progress. Not bad for a 1 man band and a wrench.
Click to expand...
Funnily enough, that is exactly why I had Lisa order me an engine hoist… So much easier than buying a keg and 4 or 5 pizzas and lining up a few helpers…

Need to pull the bed on the 85 C10 so I can wrap up the flip-notch-reinforce at the back half. Plan is to box it in, friend is a dual certified FAA/USCG welder with a 3 phase rig.

I’d love to swap a 250-6, 292-6 or old grain truck 302-6 in place of my current 262-V6. My back loathes rear mount distributors…
 
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shawn57nomad

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1981
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C10
Engine Size
250
Notches complete. Still uncertain about welding them in.
 

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