Replace Saganaw with Muncie 3+granny
 

I am interested in the reverse of swaps I have seen discussed: I want to install a Muncie 3+granny manual in place of the 3-on-the-tree manual Saginaw that came with my 71 C10 pickup. Motor is 250cu L6. I understand the Muncie is a top-of-trans / floor shift design.

My C10 is not a street rod or track truck. I use it for farm pickup and delivery. The granny gear should help driving to the barn and across pastures.

I have several questions:

- Will the Muncie bolt onto the same bell housing as the Saginaw? If not, any pointers to a bell that will work for this engine / trans combination?

- Is a new tail brace needed to support the Muncie's weight? Suggestions on any that could be used? Or is this a "fab" part?

- Is installation of a hump required? (I think so) If so, any suggestions on ones to use or avoid?

- Can I use one of the shift levers from a truck that had the Muncie? Or do I need to use a Hurst to work in the cab space between dash/heater box and bench seat?

- Are the gear ratios on the 3 "street" gears on the Muncie similar to those in the 3sp Saginaw? In other words, will my street-driving experience be similar to that of the stock trans?

Any assist would be appreciated!!

Thanks,

Robert

Re: Replace Saganaw with Muncie 3+granny
 

Hi . Welcome to the Board.
Quick answers:
1] Bellhousing for Muncie SM 465 requires a wider opening than the Saginaw 3-OTT bellhousing. 465 uses GM # 3925505 w/ 5-1/8" opening. Sag and Muncie SM 420 [4 speed] require GM #3815891 w/4-9/16" opening. A good machinist can open up the bellhousing, usually.
2] Don't know. Have to check my '68 C/10 stepside, w/292-SM465.
3] Yes. Both 420 and 465 require High Hump.
4] Don't know offhand. Data like that is in the Chassis Service and Overhaul Manuals.