4.3L Engine Upgrade

Looking for information on those who have upgraded to a GM 4.3L V6 in an early CJ pros and cons. I presently have a F-134 w/T98 four speed in a '66 CJ5.
1. Has anyone successfully mated the 4.3 to a T98. What parts will I need.
2. Novak did not have a lot of info on this particular upgrade.
3. Would it be easier to mate the 4.3 to a sm420 or sm465.
4. Any other information would be greatly appreciated on this upgrade.

 

JMO - sell the 134/T-98 combo and go with a T-18 or a SM465/420. You should be able to make the cost of the conversion kit from the sale of the 134/T-98 combo.

Cheapest would be a Jeep Wagoneer or Pickup T-18 with a Ford input shaft. You'd need to machine the bell a little, but the Jeep T-18 will bolt to your D18, just like the T-98. SM465 ot SM420 will bolt up to a GM bell (Chevy or whatever) and then you'll need the adapter kit. Search the old posts here, and read the Novak site - this has been covered a lot. I wouldn't bother trying to adapt a T-98 to anything - the Novak site doesn't cover it becasue there are better alternatives.

 

I also have a 134 with a T98, and am looking into swapping in a 4.3L chev. I believe advance adapters sells a bellhousing adapter, there are a few different kits, depending on the stick-out length of your input shaft.

 

If you spend some time looking you should be able to find a TBI 4.3 already mated to an SM465. They were available from the factory that way (in some trucks). You might even be able to buy the whole shebang for less than the cost of the AA bellhousing adapter for the T98.

 

I've got a 4.3 mated to a SM465. The 4.3 TBI is out of an Astro, the bell and trans is out of a late 70's chev half ton. The clutch and flywheel need to come from a later chev truck, forget what year off hand, but flywheel bolt pattern to match the 4.3, not the 305 or 350 flywheel in the half ton. I got lucky, I have a Rockwell standard transfer case, the predecessor to the NP 205, bolts up to the sm465. It's wide though, I have about 1/2" clearance to the passenger side frame rail. I used a chev crossmember, and welded angle on the outside of the framerail to bolt it up.

Paul

 

I am now considering a buick 231 even fire upgrade. What tranny would the most cost effective method. I have a f-134/t98/d18 set up now. Can I put the guts of a ford t-18 in my t98 case and avoid buying an adapter.

 

I might be splitting hairs here, but flywheels and clutches (among many other parts) are interchangeable between the V8 and 4.3 engines from 1986 on up. Bolt pattern and engine balance is the same.

 

:iagree:

 

Can be done but will need a T-18 Jeep/Scout output shaft to the 18 or 20 transfer case as The T-18 guts won't work with the T-98 output shaft. Nickmil