1975 Cj5 - Build Guidance Needed

I’ll be honest, I still really like the t350 option. My only concern would be giving an overfilled trans cooler setup some serious thought. But the control on the trails would be killer and it seems like it would be a blast to run around with your warm sbc.

 

no doubt about it...that's my fav option here. the PO mounted the SBC a bit too far back and moving it forward would change the height (frame rails change as you move forward)... it could be done, but at that point, i may as well consider a LS swap . I'm thinking this CJ5 is going to stay manual... the next one will be a auto though for sure.

 

I think that will be a good choice for your needs. You will enjoy street driving with a nice low synchronized 1st gear to start out in. Careful about abusing it with that SBC! You will probably end up with the T176 since it is the Jeep one that is set up for the Dana 300?

 

If you go 4 speed/Dana 300 you will want the T-176/177/178 variant. Try and find a short rear output shaft 300 also. The 300 was used with the T-4, SR-4 4 speeds which are too long and weak. Also used a T-5 5 speed which is also too long for your application. The 300 short output is 3/4”-1” shorter, I don’t remember exactly which. Short shaft can be easily identified by the speedometer hook up. The short shaft used a thread in speedo driven gear housing like an 18/20 transfer case. The long shaft uses a housing held in place by a bolt and retainer like a 231/241/208 etc. transfer case.

 

To the OP - you realize that the '80-83 CJ with the 304 would be factory equipped with the drivetrain you want? One option would be to sell the Jeep that's not equipped the way you want and look for a replacement that is.

The later Jeep would have the weaker AMC Corporate M20 rear axle, and likely have a taller (numerically lower) axle ratio than you have now. Both these issues can be dealt with. Not a perfect tradeoff, but closer to what you want, seems to me.

Pretty sure a '75 is currently emissions exempt in California, though that could change. Maybe this is important to you.

I'd also mention - I'm not sure what a T-177 is really. In the '74-80 factory parts book Jeep shows a T-176 for the CJ and six-cylinder-equipped J10s and wagons. They also show a T-178 which is the long shaft version for the V8 J10s and wagons, equipped with different gears for different ratios. In the '81-84 parts book Jeep calls them all T-176, including the short and long shaft versions. Seems the T-177 designation comes from the internet somewhere - I have not been able to make sense of it.

 

The difference in T176/177/178 is in gear ratios in CJ variants and 6 cylinder variants of the trucks/wagons which used an input the same length as CJ’s. The V-8 variant used in wagons and pickups normally did use a longer input shaft. I have a T-177 with the lower first gear and shorter input sitting on my shop floor right now. They are not a myth but are far from common. I remember Gary Holbrook (Holbrook Specialties, Holbrook Springs) coming to the shop and got extremely excited when he found we had the gear set for the T-177.

 

.. yup.. the 176\177 seem to be very similar 3:52 vs 3:82 first gear. Same case. I'd settle for either

@nickmil thanks for the heads up on the 300.. i did not know that there was a shorter one. Every inch matters in these things.

 

I have gone from a 360/t18 granny low to a LS/th350/dana20 set-up. You need a oversize cooler for the transmission. Also a dana 300 will be better (swap is on the way) because of the better ratio (2:0 dana 20, 2.62:1 dana 300). I also need to re gear my axle from 3.73 to 4.56 (was way too fast in the trail with the 36").

As for drive shaft lenght, a SBC engine is 5" shorter than a Amc v8 engine. TH350 and dana 20 are about 5" longer than a t18/dana20 combo, so it can be done.

If i ever do the dana 300 , i will have the perfect off road ratio.

But as you said i got way better control on the trail, one feet on the gaz, one feet on the brake, that's hard to beat

 

so... I know it's been a while, but just to close the loop here...life other emergencies, and forced patience have delayed me quite a bit here. I have been looking for a T176/dana 300 combo for the last year and these things are going for well north of 1400 bucks for just the trans these days. To me, that's just too much deniro for a medium-duty trans.

I have also looked into the T19 option that @timegr recommended earlier and have had the op to drive a similar Jeep with this trans. I like... I liked it a lot. both the 4 and 5:1 ratios are usable as a 1st gear, and I feel like this gives me lots of other options with the TC and differentials to explore later on. Also, this trans is fully syncro'd so it "drives" pretty well on the street as well. I had no idea how important these facts were to me until I actually drove jeeps with the SM420, 465, and t18. Taking off in 2nd gear felt awkward and a huge compromise to me. I can see why all of these would be good options for rock crawler rigs, but I wasn't a huge fan of the street experience.

Has anyone got feedback on the Novak turnkey options (1600 bucks)? Thinking either there or Craigslist (1/2 the cost, +rebuild). Still going with the Dana 300 and 4:1 kit for my TC.

Thank all of you for the opinions and feedback. Great ideas and it's been fun researching it all, I've learned a ton!