1961 gmc 1 ton

[Brady Miller]

I have a 351 v-6 and a 5 speed manual tranny. I would like to gain some road speed. What kind of tranny do I have, shift pattern below? Is a 2 speed rear end possible? If so where"s a good place to start looking? I"m not sure of my rear end ratio either.

 

[bobs ol iron]

either way you try to do it, going to be a project,, for the trans, need to find one that will fit/bolt-up to clutch,maybe a new clutch, bellhousing and pliot shaft bearing, maybe modfy drive shaft,, the rear end, to find, and/or install, maybe a newer 2-sp rear, hooking up eletric wires, maybe again modfying drive shaft..

 

[graygander]

judging from the shift pattern its a new process 540

 

[John A.]

Brady, IMO....There are 2 options to get speed out of your Old 61 Jimmy.
1-ring and Pinion Change on the rear end. GM should have what you need but will be expensive aftermarket should be more reasonable.
2- Get a hold of Gear Venders Inc I think they are in Okla. City, Okla. An Overdrive unit behind the tranny will give you an OD and still keep the Low end that this truck has always had!
Any way you go it will cost $$$$$ it just depends on what you are doing with the truck....Work, street, show, original, modified, Combination of the others! Hope this Helps!
later,
John A.

 

[Brady Miller]

Thanks john