D20 Gearset or D300 Adaptor Kit?

I’m in the planning phase for my 79 with the factory T18A and would like a lower T-case gear ratio then what is offered in my D20 (2.03:1). Novak sell a transmission adaptor kit (183-A) ($495) to join a Ford T-18A to a D300 (2.61:1) and there is a gear set conversion allowing a D20 changeover to a 3.15:1.

My two questions: Would the Novak Ford T-18A/D300 kit work with the Jeep T-18A/D300 combination? Who sells a D20 3.15: kit?

I can acquire a free D300, but I think the D20 changeover is a more sensible approach providing the kits not over $500.

 

Also, a 300 adapter for the T18 will lenghten your drive train a couple of inches.. This could cause a serious problem with rear driveshaft angles depending on the amount of lift you have.

 

Chuck, you can use the sliding gear from an early Bronco D20 to get a 2.46:1 D20. IIRC that gear is availalbe new for ca $100-150. Here's one link: http://www.off-road.com/jeep/tech/convxfer/2.46-20/ That'll put you in the same range as a stock D300. IMO the only reason to go to D300 is because you can regear it to 4:1. Since you already have the T18, your crawl ratio would be 6.32*2.46*3.54(4.10)=55(63.7), pretty respectible. A D300 would give you 58.4(67.6), and a 3.15:1 D20 70.5(81.6). Not much difference between the stock D300 and the Bronco-low D20.

If you do a search, the PNs and sources have been covered before.

<edit> try O’Brien’s 4 Wheel West (916/773-3278)

 

Thanks for the info guys.

Tim, it makes sense to go with your suggestion as I get to stay with the D20. With my T-18, a pumped up D20 3:54 axle ratio (which you just I.D. for me in another post) will be a good combination for what I need. Plus, I know where there is a early Bronco . Thanks.

 

Here is another idea.

"You will not find a heavy duty drive train as short and low geared as a the Jeep T-18 and Scout Dana 300 combination." http://www.off-road.com/jeep/tech/convxfer/scout300.html

Trick is finding one of 30,000 square light Scouts built in 1980 equipped with either the T-19 four speed or T-15A three speed.

 

Uh huh. They're out there. Last texas-pattern D300 I saw on a board was $750, but it may have had the automatic bull gear. I also have seen an '80 Scout on ebay within the past year where the seller made it clear it had been converted to a Dana 20 ... wonder how that happened?

Probably cheaper to build a 3.15 D20... have you looked at the Uber-20 articles on Pirate? http://www.pirate4x4.com/tech/billavista/Uber-20/index.html

 

if you do the 2.46:1 conversion, you need all the gears from a dana 18 AND the rear slider from an old bronco 20

 

I have now, interesting article and good reading. I plan to investigate the Bronco/D18 and Scout upgrade a bit more as you mention the scouts are out there and it took me all of one day to find one, just waiting on the owner to verify that it has the T-19.