Author Topic: 78 stepside c10 need hlp plz  (Read 3473 times)

Offline 78quickstepside

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78 stepside c10 need hlp plz
« on: August 28, 2008, 02:09:33 am »
okay i have a 78 and i already swaped the original 250 with a 3 speed for a 350 with a tko 5 speed but now i need help with this swap i need to know if the motor mounts will bi in the same location on the frame and i have a munzie 4 speed for the 396 i need to know what clutch and flywheel will fit for it and i need to know where to reinforce the frame and how to reinforce it and where can i find a trans mount ann cross member for the munzie so it will sit right in my truck and if there is any advice or tips it will be very appreciated

Offline ccz145a

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Re: 78 stepside c10 need hlp plz
« Reply #1 on: August 28, 2008, 08:18:17 am »
I do not have all your answers, but I have done a swap similar to this. I put a 396 in a '79 305 truck.

Motor mounts are the same.
No reinforcement neccessary.
Trans mount/xmem: don't know, but they do make adjustable mount for this.
Clutch/Flywheel should be straight forward as contacting Summit and tell tthem what you need.


You will need:
to realign the front end, the 396 is 150lbs heavier than a sb
aquire accessory mounts (alt, ps, A/C, fan)
a larger radiator
get a driveshaft, or have your modified.

Hope this helps, and you won't be disappointed with this swap. My '79 burned many a camaro and trans-am in it's day.
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline Captkaos

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Re: 78 stepside c10 need hlp plz
« Reply #2 on: August 28, 2008, 11:57:18 am »
You listed 2 different scenarios
1)swaped the original 250 with a 3 speed for a 350 with a tko 5 speed
2)i have a munzie 4 speed for the 396

What exactly are you working on?
If you have already swapped the I6 to the 350, you already know the frame side engine stands had to be moved from the "6" location to the "8" location
I would assume you also reused your stock crossmember for the Tko?

The engine mounts for the 350 are exactly the same as the ones for the 396, or any other motor.
The crossmember is the same for any availible transmission included a Muncie 4 speed.  The location it the only thing that should change.
The trans crossmember should have already been "braced" from the factory, nothing extra is needed.
Clutch= You should be buying this as an assembly, so you need one to fit what ever flywheel you are using for the 396 (assuming this is what you are talking about.)  If you are using a 396, the 350 flywheel will work also.

Offline 78quickstepside

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Re: 78 stepside c10 need hlp plz
« Reply #3 on: September 04, 2008, 07:55:16 pm »
sorry change of plans i got rid of the 396 and the munzie i changed it to a 454 with a B&M turbo 400 for my truck i need to know what toque converter to get for it

Offline ccz145a

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Re: 78 stepside c10 need hlp plz
« Reply #4 on: September 04, 2008, 08:01:41 pm »
What are you wanting to do with the truck and what mods on the engine? For a dd I would stick close to stock ( ~1800 - ~2000), but if you've got a wild cam then you can't do that.
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline Captkaos

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Re: 78 stepside c10 need hlp plz
« Reply #5 on: September 05, 2008, 08:53:16 am »
ditto, if the motor is stock, you need a stock converter.