Ok so Im new here but have been on other Wheelin boards...
I recently finished upgrading to a D 60 front end and D 61 rear with 4.10 gears front has a drop in locker and rear is welded.
After adding a set of 39.5's I smoked my TH 350 on the first trail.
I was smart enough to pull the TH 400/np203 out of the 78 1 ton donor truck before scraping it as the TH 350 had over 15 years of abuse since its last rebuild.
I was also just given a SM465 mated to a NP 205 that was behind a big block and the clutch is in good shape.

So now for the questions.
1. Which trans is going to be the better choice for the following.
203, 205 doubler?
Reliability?
low maint?
ovberall dourability?

2. Has anyone BYM'd a doubler adapter for adapting a 203 range box to a 205 and if so What was involved?

This is a ling to the unfortunate towing of my beast following the detonation of the TH350.

http://www.youtube.com/watch?v=v73UHzzqVM0

I'd say they're both about as bullet-proof as you can get (the 465 and 400).

You're already set-up for the auto. Coolant lines, ,radiator, etc...

You'd have to hang a clutch to run the manual box...

Parts wise, you're only a 32 input for the 205, bore your 205 for the big bearing, and the doubler kit away from finishing the project with the 400/203/305 combo.

Both set-ups will need new d-shafts to be built.

No brainer for me, go with the TH400. You'll be glad you did.

Slightly unrelated, but still a doubler tech related item... I have a round pattern 205 with the long 32-spline input gear. I also have a Ford 205 that I'm going to use as a donor for the 32-spline front output shaft. Since I already have the Ford case, I'm just going to use the 31-spline shorty input gear from the Ford case and ordered my ORD doubler kit with the Ford 203 output.

So here's the question... and it's just a thought, but can the long style 32-spline input gear be simply cut off to the correct length? In other words, can the long input be made into a shorty? I don't know off the top of my head of the splines are cut deep enough into the long input to allow simply cutting it down without have to respline the input deeper.

I'd say they're both about as bullet-proof as you can get (the 465 and 400).

You're already set-up for the auto. Coolant lines, ,radiator, etc...

You'd have to hang a clutch to run the manual box...

Parts wise, you're only a 32 input for the 205, bore your 205 for the big bearing, and the doubler kit away from finishing the project with the 400/203/305 combo.

Both set-ups will need new d-shafts to be built.

No brainer for me, go with the TH400. You'll be glad you did.

The S 10 was a manual and I left all the clutch stuff, Pedal, Master Cylinder, etc intact when I did the body swap. so Either way its more or less a bolt in.. Just wanted to get some feedback on the prefrence..

As for the Doubler kit What im realy interested in is if anyone has Back Yard Mechanic'd one... I was thinking after looking at a bunch of different designs that I may be able to use one of the mounts and some misc steel to custom make one... Im sure someone here has done this I jus needa know what was involved. AKA I don wanna spend $600-$900 on one if it is something I can make myself...

The S 10 was a manual and I left all the clutch stuff, Pedal, Master Cylinder, etc intact when I did the body swap. so Either way its more or less a bolt in.. Just wanted to get some feedback on the prefrence..

As for the Doubler kit What im realy interested in is if anyone has Back Yard Mechanic'd one... I was thinking after looking at a bunch of different designs that I may be able to use one of the mounts and some misc steel to custom make one... Im sure someone here has done this I jus needa know what was involved. AKA I don wanna spend $600-$900 on one if it is something I can make myself...

the hardest part will be the shaft between the two boxes. it is relatively simple, though time consuming, to make the adapter, but the shaft is a different matter.

Not backyard made, but I am looking at the one from Jed's Machine for $475. Send him your 203 shaft and he will cut and spline it correctly for the kit.
http://www.jedsmachining.com/

Ok so Im new here but have been on other Wheelin boards...
I recently finished upgrading to a D 60 front end and D 61 rear with 4.10 gears front has a drop in locker and rear is welded.
After adding a set of 39.5's I smoked my TH 350 on the first trail.
I was smart enough to pull the TH 400/np203 out of the 78 1 ton donor truck before scraping it as the TH 350 had over 15 years of abuse since its last rebuild.
I was also just given a SM465 mated to a NP 205 that was behind a big block and the clutch is in good shape.

So now for the questions.
1. Which trans is going to be the better choice for the following.
203, 205 doubler?
Reliability?
low maint?
ovberall dourability?

2. Has anyone BYM'd a doubler adapter for adapting a 203 range box to a 205 and if so What was involved?

Foget the Th400 and run the SM465, if you already got all t case and clutch, grab a flywheel from NAPA for $50-60 bucks and be done with it.
Nothing screams granny low like 6.55:1 crawl....:D

Slightly unrelated, but still a doubler tech related item... I have a round pattern 205 with the long 32-spline input gear. I also have a Ford 205 that I'm going to use as a donor for the 32-spline front output shaft. Since I already have the Ford case, I'm just going to use the 31-spline shorty input gear from the Ford case and ordered my ORD doubler kit with the Ford 203 output.

So here's the question... and it's just a thought, but can the long style 32-spline input gear be simply cut off to the correct length? In other words, can the long input be made into a shorty? I don't know off the top of my head of the splines are cut deep enough into the long input to allow simply cutting it down without have to respline the input deeper.
fuck it cut it what do you have to loose. if it dosent work it would have never workd in the first place if it does you save some cash. i would try to not heat it up to much tho.

fuck it cut it what do you have to loose. if it dosent work it would have never workd in the first place if it does you save some cash. i would try to not heat it up to much tho.

I won't save any cash by cutting it. I have to have an output shaft from the 203 to the 205. I either use the 31 spline Ford gear or the 32 spline Chevy gear.... either way I had to buy an output shaft. Since I don't have a lathe and would probably have to pay someone to cut it down, I just ordered a Ford output shaft for the range box when I ordered my doubler kit. Swap the Ford input gear into the Chevy case when I have it apart to put in the 32-spline 205 front output shaft, and I'm done.

Not backyard made, but I am looking at the one from Jed's Machine for $475. Send him your 203 shaft and he will cut and spline it correctly for the kit.
http://www.jedsmachining.com/

Thanks Red Chevy, Thats the best price Ive seen yet on a kit... Im still going to look at building one myself but I know where to go if I am unsuccessfull.

Ok next question. I think Im going to drop the nv465 in and give it a try...
I have the fly wheel from the truck it came off of and this is what I know.
it was a big block 454 that the trans came off of. The guy I got it from says that the big block was internally balanced and I may need a different flywheel.
Im puting it behind a slightly built 350...
Will this flywheel/clutch work or do I need a different set???

Bah... shoulda read SM465....

I would run the SM465 because even with out a doubler your crawl ratio would be 52:1! with a doubler it would be 104:1!!

if you put a flywheel from a standard 454 on a 350, you will have problems. GM never made an internally balanced 454. if its internally balanced, its either not a stock 454 crank, or its a 366/396/402/427 crank. *which would mean you got ripped off on the 454. If its an aftermarket internally balanced crank, you can bolt up to a regular internally balanced 262/265/283/302/305/307/327/350 flywheel and not have a problem. Unless, of course, you have the one peice rear main seal engine made from 87 and up.

buy a new clutch.

Just me, but I would much rather have the auto than the manual. the SM465 is tough. so is the th400.

if you put a flywheel from a standard 454 on a 350, you will have problems. GM never made an internally balanced 454. if its internally balanced, its either not a stock 454 crank, or its a 366/396/402/427 crank. *which would mean you got ripped off on the 454. If its an aftermarket internally balanced crank, you can bolt up to a regular internally balanced 262/265/283/302/305/307/327/350 flywheel and not have a problem. Unless, of course, you have the one peice rear main seal engine made from 87 and up.

buy a new clutch.

Just me, but I would much rather have the auto than the manual. the SM465 is tough. so is the th400.


Ok so If Im reading this right The flywheel that came off of the 454 is a bad isea for my small block. So I should buy a new clutch and flywheel.. No prollem..

I do plan on eventually droping the TH400 in but Im going to run the 465/205 combo this summer so I dont have to wait another year.. In the mean time Im going to use the th 400/205/203 that I have extra to build the doubler for next year...

This way all Ill fry is mebby a clutch which is realitivly cheap...

Thanks again