SM420 or.....

[blackcj71]

Heres what i got going on. I picked up good running vortec 4.3L and im trying to figure what trans to get. I currently have T18 with the granny first gear (6.73 or something close to)sitting behinde my old 4.2L and Love it, and would like to keep it. BUT looking at adapters and all that parts i need to mate the chevy motor to t18 might get expensive. So i've been looking at SM420 or
SM465 thinking it'll be cheaper and easier to go that route. So who's running what and how do u like it... The rig wont be seeing hwy or anything so 5th gear like NV4500 has wont be something ill need. :corn:

 

[mjp1080]

I'd go with the sm465, their strong, cheap, reliable and have a real nice granny gear in them, I think its 6:55. Plus their really easy to find and get parts for.

 

[64FJ40]

I have an sm420.

I'd get an sm465.

Too many reasons to list, but the only advantage the 420 has is a little lower granny gear. But the difference is less than 10% and all the other benefits of the 465 more than make up for it IMO.

 

[Toyoda1]

sm465, and my freinds sm420 pops out of 3rd a lot. But the granny gear is freakin sweet on the rocks.

 

[sucmah]

dont you only have to drill out two bosses on the t18 to get it to bolt up to the chevy bellhousing? I think novak has the detailed instructions.

 

[crash2]

Don't run an sm465. They are too light and too weak :;

 

[blackcj71]

Don't run an sm465. They are too light and too weak :;

PUH!! i was searching on snort and saw thread you couldnt even lift the dang thing off your bench!!:haha: weeny.

Are they're different stlye SM465 say...output splines??

 

[crash2]

PUH!! i was searching on snort and saw thread you couldnt even lift the dang thing off your bench!!:haha: weeny.

Are they're different stlye SM465 say...output splines??

My bad--thought it was opposite day

There are 2 different 4x4 versions. one is a 10 spline and one is a 32 spline I believe (or 30). But there are 2 different versions (psssst--- on Snort--shame on you bad bad bad spenser :flipoff: )

 

[sucmah]

newer 465's(80ish and on??) have the 32 spline output. 4wd models have about an 9" shaft though, the 2wd's are only 3.5-4" and 32spline and advanced makes an adapter for the 2wd models making the newer 2wd ones your best bet for strenth and packaging. I was wrong, all 2wds are 35 spline.

 

[crash2]

newer 465's(80ish and on??) have the 32 spline output. 4wd models have about an 9" shaft though, the 2wd's are only 3.5-4" and 32spline and advanced makes an adapter for the 2wd models making the newer 2wd ones your best bet for strenth and packaging.

So I know they ran a 203 behind the 465 so did they also make a 10 spline 205 also? For some reason I thought the 32 spline was for the 205 version.

 

[mjp1080]

So I know they ran a 203 behind the 465 so did they also make a 10 spline 205 also? For some reason I thought the 32 spline was for the 205 version.

Yeah, they made one and I've got it, It works great. However it has the ten spline not the 32.

 

[PORTER]

Are you set on a manuel? If not t-350, or 400 with the proper gearing is a winning combo.

 

[mudracer]

My bad--thought it was opposite day

There are 2 different 4x4 versions. one is a 10 spline and one is a 32 spline I believe (or 30). But there are 2 different versions (

32 spline, 10 spline. late model 2wd versions were 35 spline, as well, but nobody makes an input that size. but you new that, crash.

oh, and for the np 205, there is a 10 spline version that bolts right to the sm465. these had the early "racetrack" pattern. early versions used a smaller bearing and a male input, with a collar. later versions with the 32 spline input have a female input, and it sticks out of the case forward about 4 inches. you can tell an early case from a late case by the input length/design and the adapter pattern. later models use a round face with six holes LIKE a ford, but not the same as a ford. Early models used a "racetrack" adapter

the later version with the 32 spline used the round faced np205 housing, and you could use the th400 and adapter or swap the case directly to the 4 speed with the roundfaced adapter and 32 spline output shaft.. 87 and later, i believe.

 

[crash2]

Waller brings it awn


I have only dealth with the 32 spline 205's behind 203 doublers so far...

SO for the 10 spline 205's that bolt up to a 465--they musta been goofy looking with how the back of a 205 looks...

All I know is the 456 is a heavy pig. When mine broke I had ful awn battle to rip it apart due to how the countershaft is.....

 

[sucmah]

So I know they ran a 203 behind the 465 so did they also make a 10 spline 205 also? For some reason I thought the 32 spline was for the 205 version.

The 32 spline 465 was also used with 208's and 241's.

 

[blackcj71]

Are you set on a manuel? If not t-350, or 400 with the proper gearing is a winning combo.

Ya im seriously considering TH350 cuz i already got one and it'd be nice to put it in drive and go. Im just affraid i'll be missing my granny first gear to much.

 

[crash2]

Love my manual---that is all

 

[CrustyJeep]

You already have the trans/case adapter, whichever case you're running (20 or 300?) I believe, as was already mentioned, that you can redrill a chev bellhousing to accept the T18 bolt pattern. That's exactly what I'd do. Otherwise, the (pick a tranny)/case adapter will cost you somewhere in the $500 range.

Plus you'll deserve to be bitch slapped for letting a wide ratio Jeep T18 go :flipoff:


(And I love my manual too )

 

[sucmah]

depending on the make of the t18, you dont drill the bellhousing, you drill the tranny face. Read this http://www.novak-adapt.com/knowledge/t18_t19.htm

 

[CrustyJeep]

There's also the Jeep Iron Duke bellhousing (chev engine to Jeep tranny)... If you can find one.

In the above article it says to turn the diameter down where the throw out bearing slides on the input nose. I used a Ford heavy duty throw out bearing and didn't have to do any machining. I just had to do a little grinding to make the Chev throw out arm fit the bearing sleave.

You'd still have to have the large diameter turned though, so it will fit into the bell housing. Any machinist could do that in a matter of minutes, very very simple.