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Engine Swap Question

Engine Swap Question
G

Gsmithl10

Jeeper
Posts
45
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Location
Sharpsburg, Georgia
Vehicle(s)
86 CJ,Dana 35, AMC 20, 258 I6, T176, Dana300.
Will a 350 or 302 "bolt up" to a T-176 or does it require an adapted bellhousing? I'm wanting more power and can't decide between I6 with 4.0 head conversion or V8.
 
Thanks for the link. Told me everything I needed to know. I think I'm gonna put a 4.0 head on the I6 and change the gears.
 
Gsmithl10 said:
Thanks for the link. Told me everything I needed to know. I think I'm gonna put a 4.0 head on the I6 and change the gears.
Click to expand...

Sounds like a solid plan. You may have to change carriers for your Cj as well. Alot of the late 80s Cjs had 2.72 gears and small carriers. Being that yours is an 86 check for a Dana 44 rear as well.
 
I've got an AMC20 in the back and Dana in the front. How do you tell the difference in carriers? Any gear recommendations? I'm running 35s. It will mostly see asphault but I do want a capible off road machine.
 
Gsmithl10 said:
I've got an AMC20 in the back and Dana in the front. How do you tell the difference in carriers? Any gear recommendations? I'm running 35s. It will mostly see asphault but I do want a capible off road machine.
Click to expand...

Personally Id recommend 4.56 gears for 35 in tires in your scenario. I mentioned the small carriers due to the year of your Cj. Your Cj would be a dog with 35 in tires and the 2.72 gears alot came with stock. Maybe this is why you were considering a V-8 swap?

If you want to check what ratio you have heres how.

Jack up the rear of the Jeep and put it on jackstands. Put a mark ( piece of tape , chalk ) and rotate the tire 1 full rotation if you have a locker , 2 full rotations if you dont. While your rotating the tire the correct amount of times count the revolutions of the driveshaft. This will give you the gear ratio.

Example: locker 1 full turn of the tire nets 4 turns of the drive shaft. Your ratio is 4.10.
 
Also there may be a tag on one of the differential covers that would have the gear ratio stamped on it. This assumes that the diffs haven’t been molested of course.
 
Petescj thanks for the info. I did not know that there was a difference in the amount of times you had to turn your tire if you had locker.

And yes this is part of the reason for wanting to upgrade the engine. I don't think its the original engine and the compression is alittle low. 130psi. on 4 cyl, 120psi #6 and AMC 150 on #1.

Saddle Tramp I'll definatly crawl under and check the diff.

Thanks for the help
 
Jeeps are built, not bought - that includes the powerplant/drivetrain. That said, I've had a built AMC 304 and now a 350 in my CJ5 and must say that I like the 350 better - lot cheaper to make go fast. A chevy V8 conversion is easy, bolt-in engine mounts are available and not too pricey. I managed to keep the swap fairly inexpensive by using as many stock components (either AMC or Chevy) as possible. For instance, I had a chevy NP435 Transmission that I wanted to use that would mate up to a stock mid-80s chevy truck hydraulic clutch bellhousing. I used the chevy clutch slave cylinder and the 4 cylinder Jeep hydraulic clutch master cylinder to complete the clutch "linkage". I did have to use an adapter between the Transmission and Dana 20 Transfer Case though. Chevy/CJ headers are easy to come by as was the chevy conversion radiator. All else pretty damn easy. In the long run, more/cheaper parts available to make a chevy V8 go fast...which I like.

Getting ready to built a CJ for my daughter and will likely stay with the AMC 304 just to keep the build simple and quick.
 
Petescj said:
Personally Id recommend 4.56 gears for 35 in tires in your scenario. I mentioned the small carriers due to the year of your Cj. Your Cj would be a dog with 35 in tires and the 2.72 gears alot came with stock. Maybe this is why you were considering a V-8 swap?

If you want to check what ratio you have heres how.

Jack up the rear of the Jeep and put it on jackstands. Put a mark ( piece of tape , chalk ) and rotate the tire 1 full rotation if you have a locker , 2 full rotations if you dont. While your rotating the tire the correct amount of times count the revolutions of the driveshaft. This will give you the gear ratio.

Example: locker 1 full turn of the tire nets 4 turns of the drive shaft. Your ratio is 4.10.
Click to expand...

I've got 4.27 gears in my CJ5 that I run with either a set of 15/35-15 TSLs or old 36 Buckshot Mudders. Gearing is PERFECT with a good running V8 and my Transmission /Transfer Case combo and doesn't cause excessively high rpms out on the highway. Lot of factors involved with picking the correct gears - suggest that you figure out what motor you are going to use first, then tire size, followed by Transmission /Transfer Case gearing, and use before settling in on axle gears. You really want to get it right the first time.
 
Alright, I've decided to keep the I6. Gonna run the bigger 4.0 head from odessa with a comp cam part # 68-231-4. Lift is int 463/ 485 exaust. Bore the cylinders out (just what is needed) and put on the 4.0 header. My question is... Will my weber 32/36 and stock intake work for the time being until I get the funds for a clifford intake and bigger carb. Not gonna get FI trying to keep it as simple as possible.
 
BIGTRUCKNUT said:
I've got 4.27 gears in my CJ5 that I run with either a set of 15/35-15 TSLs or old 36 Buckshot Mudders. Gearing is PERFECT with a good running V8 and my Transmission /Transfer Case combo and doesn't cause excessively high rpms out on the highway. Lot of factors involved with picking the correct gears - suggest that you figure out what motor you are going to use first, then tire size, followed by Transmission /Transfer Case gearing, and use before settling in on axle gears. You really want to get it right the first time.
Click to expand...


Bingo! I stated this in another thread. You cant just go by tire size and gears using the gear chart. You need to figure out your entire drive line and what you are shooting for. I wanted something that had decent road manners like 70 mph and still get the best fuel mileage out of it I could. I am changing up my entire drive line and I think I have it down pack on what I want to do.

This is my plan, AMC 304 rebuilt unknown specs (POx2) replacing the intake with lighter one and Q jet carb, dissing the T-4 for an early 80's F450 rollback Ford 2x4 T-18A (granny gear) with PTO ports and doing the novack conversion to mate with the Dana 300 Transfer Case . I am swapping out 2 piece axles for 1 piece and installing 4:56 gears to turn my 35's.

Doing this puts me around 2600 RPM's doing about 72 mph. That's perfect for me. My crawl speed will be in the high 70's to 80's which is for serious rock crawlers and I don't do that. But I want to be able to do so if I chose.

So I think I have a decent all around built plan. Its a little more homework then just saying I have these tires what gears should I run. Some run 5:13 gears or something like that. Good luck...
 
Gsmithl10 said:
Alright, I've decided to keep the I6. Gonna run the bigger 4.0 head from odessa with a comp cam part # 68-231-4. Lift is int 463/ 485 exaust. Bore the cylinders out (just what is needed) and put on the 4.0 header. My question is... Will my weber 32/36 and stock intake work for the time being until I get the funds for a clifford intake and bigger carb. Not gonna get FI trying to keep it as simple as possible.
Click to expand...


Throw that Weber carb out. Don't waste your time putting that piece of :dung: back on your nice rebuild. I have that same carb on my jeep and it doesn't like hills. I always stall on the climb and it's not fun rolling back down steep inclines with little ones in the back. I did some research and found this is a true issue for the Weber. There is a piss poor solution and that is to turn your carb around 180 degrees. The problem doesn't go away completely, it just makes it stall coming down angle vs on the climb. So the thought behind that idea is you can clutch brake and start your engine as you decent down the hill vs stalling on the climb and getting screwed.

I plan to install the Q-Jet carb and something you should look into if you are planning a bigger carb. Just my .02. I've been dealing with this issue for 7 years now and I can't wait to drop my AMC 304 in the bay...
 
A ford 5.0 will bolt up to a T-176 (177) if you get a junk yard bellhousing out of an 80"s Ford truck or van with either the 300 I6 or the 302.

That's what I'm working on right now.
 
Alright the block and AMC 258 i6 / 4.2l head are with my machinest now.... I can get my AMC 258 i6 / 4.2l head built very similar to the odessa HO 4.0 head, valve size, springs, etc. My question for everyone is... Is the 4.0 head really worth the extra funds???? Or could a build AMC 258 i6 / 4.2l work just as well?

I have some resurvations about spending the money on the swap. As well as the push rod size, preload, and mounting in general. Any imput/advise is appreciated.
 
Its not just the components that make the 4.0 head better. I dont remember where i saw it, but ive seen a diagram that showed how the flow was better. The intakes on the AMC 258 i6 / 4.2l head come in at a 90° angle, where the AMC 258 i6 / 4.2l comes in at 45°. That much more efficient flow is whrre alot of the improvement comes from
 
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