Does anyone know if a T-4 Tranny will mate right up to a Dana 300 Transfer case without any modifications? I am swapping my T-150 tranny to put in a T-4.

Yes it will. The dana 300 came behind the T-4 82 through 86 CJ's; the better question is why would you want a T-4? Light duty tranny at best.

I don't do much rock crawling but I do like to wheel, and I wanted something I could use as a daily driver. Any other suggestions for a stronger tranny? I have a CJ-7 with a sb 350.

Dude dont even consider putting a T4 behind a 350. It will break!!! There are many other options out there, too many to list. Search a little and will find all of the answers.

What are you running now? You'll need an adapter either between the engine and tranny, or between the tanny and transfer ... or both. Choose wisely and take the cost of adapters into consideration.
CP

I was running a T-150 with a Dana 20 but the rpms where up there when running at higher speeds. I was wanting another higher gear for highway/daily driver use.

I do have access to a TH350 automatic and I already have the adapter plate for the transfercase. I would just need a dana 300 transfercase for it. I'm just not sure about going automatic though?? And, I'm sure it would hold up just fine behind the 350?

Any comments would be appreciated!

If your trying to reduce your cruise RPM on the highway then you'll need an overdrive transmission. The T-4 won't gain you anything since both it and the T150 are 1:1 ratios in high gear. Acutally the TH350 is also 3-speed so it's not going to be any different either if you're only looking at cruise RPMs. You'd need to look at a TH700R4 (4L60) if you want the overdrive.

What axles/ratios/tires are you running?
CP

I have Dana 30 front and AMC 20 rear w/33" tires. I don't know the gear ratios though?

As for the TH350, a friend of mine had it in his Blazer and he said it did OK on the highway?? I know it's a 3sp but I was thinking the 3rd gear might be a little higher in it?

How fast are you trying to drive? If your front 30 hasn't been messed with then it might have a thin metal plate attached under some of the coverplate bolts, it will have some numbers along with the pinion/ring gear counts. Also the 20 rear will have stamp marks on the right side of the housing. But if anyone has replaced the gears then those factory marks are wrong anyway.

Except for overdrive transmissions, the high gear will always be 1:1 (1 to 1) or 1 revolution input equals 1 revolution output. So the TH350 in 3rd is the same as the T150 3rd, and the T4 4th.

Your buddies blazer probably had 2.73 or 3.27 gears so it would run "faster" than yours which appears to have 3.54 or 3.73 gears.

If you care so much about your cruise speed then you'll have to spend the money for an overdrive transmission. Otherwise you have lots of options for 4-speeds which can handle the 350 engine. Check out AdvancedAdaptors and Novak, both have very informative catalogs.
CP

CP801,

Thanks for all of the good information, you have helped me out greatly. Highway driving is not that important to me. I just thought I could change out the tranny and achieve the smoother higher gear while I was tinkering with my jeep. Besides, someone gave me the T-4 and I though I could use it. As I found out, it does not seem to be a good idea behind my engine. I may look at buying a T-177, or T-176 from someone as long as it will bolt up to a Dana 20 transfercase. It looks like a cast iron transfer case and therefore hold up as well at the T-150 that I removed from my jeep. Do you know anything about these trannys and if they will directly bolt up to a dana 20 TC?

I really appreciate the great information!