I have a TH400 that I was told is out of an H1. It has a 2.5" stick out 32 spline output shaft. My front axle is a Superduty 35 spline D60 so I'm needing a driverside drop tcase.
I'm in the middle of build a cage/backhalf chassis, 2" rogue fab die, swapping from leafs to king coilovers, front and rear stretch, 6.0 swap, seats, harnesses, etc so my wallet has been used an abused these last three weeks collecting parts and buying tools.
I'm trying to keep this as budget friendly as I can
Considering last night was the first time I've ever even seen a picture of an Np205 I stayed up late and did some reading.
From what I gather is the Ford NP205 (married) is a 31 spline input shaft. Some GM np205 cases used a 32 spline input shaft along with a bigger bearing. The Ford 31 spline case
uses the same size bearing as the GM 32 spline input case.
GM also has 10 and 27 spline inputs but they are of no use to me.
The Ford also has 32 spline fixed yoke outputs vs GM 205s which can have either a fixed or slip yoke.
The Ford NP205 uses a 6 bolt pattern and GM is 8 bolt until they went to 6 bolt like on the Ford. The NP 208 which came mated to TH400 from the factory also uses the same 6 bolt pattern.
If I swap the GM 32 spline input into the Ford NP205 case I can use the factory TH400/NP208 adapter? Is there a more economical solution?
Is there anything I'm understanding wrong about these cases?
My build is running 37s, 5.38 gears in the axles, and I plan on stepping up to 42s asap.
With a stock 6.0, th400, is the 2:1 low going to be enough for 42s?
Should I stop being a bitch and pony up to build a 203/205 doubler or does that put me in used atlas territory?
I'm in the middle of build a cage/backhalf chassis, 2" rogue fab die, swapping from leafs to king coilovers, front and rear stretch, 6.0 swap, seats, harnesses, etc so my wallet has been used an abused these last three weeks collecting parts and buying tools.
I'm trying to keep this as budget friendly as I can

Considering last night was the first time I've ever even seen a picture of an Np205 I stayed up late and did some reading.
From what I gather is the Ford NP205 (married) is a 31 spline input shaft. Some GM np205 cases used a 32 spline input shaft along with a bigger bearing. The Ford 31 spline case
uses the same size bearing as the GM 32 spline input case.
GM also has 10 and 27 spline inputs but they are of no use to me.
The Ford also has 32 spline fixed yoke outputs vs GM 205s which can have either a fixed or slip yoke.
The Ford NP205 uses a 6 bolt pattern and GM is 8 bolt until they went to 6 bolt like on the Ford. The NP 208 which came mated to TH400 from the factory also uses the same 6 bolt pattern.
If I swap the GM 32 spline input into the Ford NP205 case I can use the factory TH400/NP208 adapter? Is there a more economical solution?
Is there anything I'm understanding wrong about these cases?
My build is running 37s, 5.38 gears in the axles, and I plan on stepping up to 42s asap.
With a stock 6.0, th400, is the 2:1 low going to be enough for 42s?
Should I stop being a bitch and pony up to build a 203/205 doubler or does that put me in used atlas territory?