I have an 87 6.9 RWD and want to swap it into an 84 6.9 4x4. Both trannies are automatic. I am concerned about transmission to engine bolt pattern. I would assume that it would fit but you know what happens when you assume.

The reason for the swap:

87 compression: 500 450 480 500 480 440 480 500
84 compression: 360 400 360 420 340 420 380 380

and oil pressure is good in the 87 too. I have owned the 87 since 6500 miles and have changed the oil religiously but the body sucks. The 84 I just picked up has a good body.

The 87 has a C6 tranny but I am not sure what is in the 84. The tranny oil pan does not look the same. Be nice if I could switch tannies too since I have always changed the tranny fluid.

 

the engine should be a direct swap in, i am almost positive that it will bolt right up. If you wanted to put in the trans you have as well, it might just be a good idea and yeah it should meet up fine with the trans mount. Minor fabbing at most would be required. Dont quote me but the two are so close in year, it should be fine.

 

The motor is very swapable, the transmissions are not ... They are different because of the 2wd and 4wd differences.

Bell housing bolt patterns are the same, no problem there.

The 87 has the newer style glow system, The wiring harnesses are different, you'll want to keep the 84 engine harness and glow system, then apply it to the 87 motor, should be a direct swap.

Unless you want to keep the newer style glow system (recommended) then you have to splice the 87 engine harness into the 84 chassis harness.

-Enjoy
fh : )_~

 

Why don't you just swap the cabs?

 

An engine swap is an afternoon to a weekend project. Swapping a cab is a much more time consuming affair.

Jason

 

The 84 has a shorter wheel base because there is no back seat as in the 87 so I am not switching cabs. I plan on keeping the new glow plug system. In fact I just came back from the wreckers on Thursday with a new style harness, controller and all 8 glowplugs checked out and were Berus. This all came out of a 7.3 IDI mini-bus with less than 100000 miles on it. It even had Ford belts. Too bad I canibalized the motor, I bet it was in good shape too. No oil leaks either. Don't know why they did not pull the motor and put it in inventory. Grabbed the battery cables, Ford too and in good shape. Also got fuel/water separator unit which I would like to put in my truck. Got a dip stick tube too. All this for $50. Got to love the u-pick-it yards.

 

they don't pull the motors cause we are too cheap to pay a junkyard 1500 and up for a motor they've pulled and prepped,

plenty of them 7.3 busses in the junkyards round here too the E4od didn't hold up well in a stock form with that much weight