Later model 4-speeds behind an Inline 6?

Will an Muncie M21 be a good match behind a 275hp to 300hp 270 Inline 6? Just curious if this is a reliable set-up. I want a decent streetable combo that has some good tire chirping power in a 2,300 to 2,500lb fenderless rod...and I'd like to drive the highway at 70 without the engine ringing out of the frame. Anyone with experience putting later model 4 speeds behind the I6?

 

I'm sure a M-21 would hold up just fine!.....Lots of inliners are using T-5's with good results

 

I have a T-5 and two T-10's also...wonder if one of those would be better in this application. I have a Hurst shifter and linkage for the M21, so that's why I'm leaning that direction. Plus it's a wide ratio, which seems like it mike be better combined with the torque and low-end of an I6.

 

The five speed T5 is a great choice; several versions with slightly different ge****ts would work great. Another to consider is the Saginaw four speed that came in Vegas. It had a 3.11 first gear, and would likely be inexpensive, and easy to adapt.

 

I ran an M21 behind a fairly built 230 a lot of years ago. Sixes make plenty of torque, so a wide gear spread is good. I thought the ratios were too close together. A T5 would likely be a good candidate with an overdrive to boot.

Devin

 

I had a M21 in the 48 with a six, 283 and 350 and as 4 pedals said the gears are pretty close together and that trans likes at least a 3.40 rear end if not a lower ratio than that with the higher first gear ratio.

 

I ran a 3:12 Saginaw 4-speed behind a 235 with a 3:56 rear. It worked great.

 

the 2.20 first gear ratio isnt very ideal for a 6. the saginaws & the t5's work out pretty nice with their lower first gears

 

I 'm planning on using a A-833 hemi 4 speed behind my Chrysler straight 8 . Rob.

 

a munci would take a 427 and hot 396 with no problem. i think that inline six will not over power it. yes they will bolt right up.

i have been using the saginaw 4 sps. in 3.25 and 3.50 first gear for sixs and small v8s.

take the first gear ratio maultiply it by the rear ratio. if it anything less then 10.00. the car or truck will have problems starting out.

a 3.55 rear with a 2.20 trans will come out to 7.81 unless you are running a big block you are going to have problems getting it moving.

change the trans to a 3,25 you end up with 11.49. which means your small block and i6 will be happy.

 

I ran a 2.52 low muncie for a while with a 2.93 rear. and it wasn't good. This is a heavier car, 3600 lb 54 210.

Now I have a 3.50 low Saginaw and it's perfect. 1-2-3 have nice steps and works great for around town. 3-4 is a big jump, kinda like the 4-5 on a T-5.

anyway, depends on the rear and tire size trhat you run.

 

mid 80s chevy pickup had a 3 spd plus overdrive. I forget the production option code
but there are a couple threads on it. came from gm with a hurst sourced shifter. I bought a 250 with one behind it.

 

I have a Saginaw too...I believe it's a '68 out of one of the Camaros we parted out years ago. I'd love to have the T5 with overdrive...don't think either of mine have the OD top gear. How do I tell?

 

I ran a T-10 behind a 235, and it was a sweet combo

 

I think this is the one GM labels as MY6, a New Process box same as a A833 but it has a Chev. front bolt pattern & input shaft. Lots of info about them on Mopar sites. 3rd is direct, 4th is O.D.

 

I'm going to be on the lookout for a T5 with OD or an MY6, but first I'll make sure my Saginaw isn't rebuildable...

 

i am running a t-5 behind my 200 straight 6, with 3:80 gears in the rear.

i only run about 2700 rpm's while going 70mph down the highway

 

Are there casting numbers I should look for to find a T5 with the best O.D. ratio? Anyone know where there might be one for sale? I'm not sure what the final ratio is on the T5's in my yard... ID help?

 

Do search for T5 here. Flat Ernie has compiled a lot of great information on the T5 transmission. There have been countless discussions about the T5 in many applications.

 

I also use the Vega Saginaw. Works great. Many laps at El Mirage and Bonneville. A few at the drags. Now on the street. Pretty loyal trans I would say.

 

I'm wondering if someone can explain the specific issue I'll face with the M21? Is it that I won't have enough low-end grunt to get it moving in 1st gear, or that I'll be ringing out at hwy cruising speed? And with either issue, can it be corrected with different rear end gearing? OR, is the T5 the best option simply because it'll give me both low 1st AND an O.D. for cruising speed? I'm guessing the last question is the reason, but I'm still wondering the issues with the M21... Thanks guys

 

The M21 is more than enough to get the job done, but the drivability of the t5 makes it the popular choice. old I6 engines aren't real rev happy. remember they came with powerslides and **** 3 speeds for the first 30 years.