Doubler info

upnover

upnover

Grumpy, decrepit Old Man
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Joined
Mar 20, 2005
Location
Morganton NC
Not sure if this belongs here or General tech, but here goes.

I have a friend who has a 350 turbo, 205 combo. He wants to go to 42's (now running 38's) and as I see it his options are:
1. Re-gear front and rear diffs Now running 4:56's
2. Get the new 3 to 1 for the 205 ( I think it is available now somewhere)
3. do the doubler 203, 208? and his 205

I have no clue as to what all is involved in doing the doubler. ie peices needed, adapters, what you use and what you don't use.
Sooooooo..... If anyone has in depth detailed info on this I would very greatful.

Thanks
Chip
 
Check out offroaddesign.com for a bunch of doubler info. They sell doubler kits, but there are other kits your friend should investigate too to make an informed decision before buying one. Maybe other folks can chime in with other places selling kits?
 
he will have less $$$ in re-gearing than in the doubler trust me i gist orderd ORDs doubler for the 203 to 205 and it ran about 1165 with the 3 stick set up
 
Depends on what it's going in.. in a SWB vehicle, a doubler may not be such a great idea, due to driveline length (an issue with mine)

If you've got the length, the doubler is a very flexable option because of the ratio choices you get..

If he goes much lower than 4.56's, I think he'll be taching high on the street (if it sees street miles)..
 
My breakdown was something like:

NP205: $100
NP203: $100
doubler adapter: $400
32spl flanges: $200 (maybe $250??)

Plus $100-150 in paint, gasket set, shifter pieces, etc. Easily $1k total.

Probably more expensive than regearing two diffs, but there aren't many diffs with 9.12 gears, either. That said, I've found that two gearboxes with 2:1 reductions is nice, but having one gearbox at 2:1 and one with a 2.7 or 3:1 reduction would be better. I do use the low/low (109:1 in my case), but being able to split gears would be awesome.

Wagoner sells NP203s with 3:1 gearsets for around $1k.

Oh, and you'll want to get into 31spl and 32spl tcase inputs to get away from any chance of breaking input/output shafts. The 27spl stuff doesn't break easily.... but it does break.
 
dont forget about $$$ to modify driveshafts for a doubler as well - plus the added weight. IMO, i would regear the diffs or do the 3.1 in the t/case. Id personally shoot for regearing diffs...plus you can probably sell your current r&p to regain some $ spent.

I have a healthy v8 and 4.56s, I wish I had a bit more gear to have high range a bit more useful. 4.88s or even 5.13s would be peachy in my book.
 
I am just about two weeks ahead of you in researching this for my buddy too. He has a 350/TH350/203, 4.56's, and 40's. When he stepped up to the 40's it pretty much killed the trucks performance. Below are some good sites. I would read all of this stuff. These are the only three suppliers I have found for doublers. I like the Northwest Fab one the best, but Jed's has the best price. I have talked to the guy at Jed's a couple of times already and he is super nice and helpful.

http://www.offroaddesign.com/catalog/doubler.htm

This guy makes the doublers that Stazworks sells from what I have been told
http://www.jedsmachining.com/

Lots of folks on Pirate like this group the best
http://northwestfab.com/203-205adaptor.html

Danny
 
you can also build your own if you have acess to machine shop. there are drawings on pirate for the plates then you use a peice of 3" pipe about 2.75 long and machine the bearing retainer into the 203 side plate. blacksheep on pirate has made several of these.
 
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