Transmission Swap

Engine, transmission, rear-end, driveline, fuel system etc..
Post Reply
61stepside
Sweptline.ORG Member
Sweptline.ORG Member
Posts: 103
Joined: Fri Jun 30, 2017 8:01 pm
City: SoCal
State: CA

Transmission Swap

Post by 61stepside »

Thinking about swapping my three on the tree for a four-speed, Were four speeds available behind slant sixes in 61 D100's?

User avatar
Hobcobble
Forum Moderator
Forum Moderator
Posts: 14573
Joined: Wed Dec 31, 1969 6:00 pm
Location: Lockport, NY

Re: Transmission Swap

Post by Hobcobble »

61stepside wrote:Thinking about swapping my three on the tree for a four-speed, Were four speeds available behind slant sixes in 61 D100's?
My '61 Slant Six D200 came originally equipped with a NP420 4spd tranny. It is not
synchro'd in 1st or 2nd gear though. If you could find a NP435 4spd that has provisions
for the parking brake drum, it would be a good candidate, as its synchro'd into 2nd gear.
These Sweptline trannys will bolt to your current bell housing. Your drive shaft length
may possibly need to be addressed. :thinking You'll need to find a drive line tunnel
cover with the hole for the shifter. Try the Parts Wanted section. :idea As a caution, the
larger series NP trannys might have too large of an input shaft. Someone who owns
a 400 or larger truck might be able to fill you in.
John

User avatar
dodgeboykim
Sweptline.ORG Pioneer
Sweptline.ORG Pioneer
Posts: 3003
Joined: Wed Dec 31, 1969 6:00 pm
City: Chilliwack. B.C. Canada
State: Foreign
Location: chilliwack.

Re: Transmission Swap

Post by dodgeboykim »

400 series and larger do indeed have a larger input shaft clutch spline. Might still be able to use that style trans but out put yoke is very large for U joint.
Not sure if smaller U joint yoke can be installed on output.
My truck is younger than me.
66 W100. 70 D 500 , 69 Hiab Speed Loader. 96 Ram 3500 Club Cab Cummin's 5 spd. 97 Ram 1500 Club Cab 5.9 gas auto. 83 W200 LB Propane 360 auto 09 Yammy Rhino 700.

User avatar
powerwagon54
Sweptline.ORG Pioneer
Sweptline.ORG Pioneer
Posts: 1335
Joined: Wed Dec 31, 1969 6:00 pm
City: Washougal
State: WA
Contact:

Re: Transmission Swap

Post by powerwagon54 »

I have the 435 with the e brake. pm sent

Post Reply