How much difference in the internal size on a 391 vs a 390. I have rebuilt my 391 several times over the years in my f-600 with only stock parts used for hauling grain. Is there any advantage using it as a performance motor. Are the cylinder walls thicker? I know the heads are completely different. I have a couple of rebuildable old 391 engines laying around. I also have access to some (3) 428PI motors in the old barn of my neighbors. So my question is can I use a 361/391 block and the 428 to breed them together. I would prefer the 427 rpm range. Also have a 410 crank as well. We did a lot of this stuff 40 years ago as kids so its been awhile. Please forgive my ignorance.

 

Pigfarmer05 Welcome to and the FE Forum

I am a little taken back with your wording, I would have thought that a grain hauler may have had it's engine rebuilt maybe once in 45 years, simply because there would not be that many miles put on them, not several times.

The FT 330/361/391 truck engine are same house engineered series with the FE 352/360/390/410/428/428 but not very swappable. The FTs were designed for lower rpm torque where as the car FEs would spin em up and run the speedos out into triple digits. I would imagine 75-80 would max out an ol grain truck, but might manage an hour of 2-3mph.

I believe I read here yesterday the the FT may have been front-rear mount where as the FEs were side mount also. I believe some of the FTs ran sodium valves for temps where the cars didn't.

How many more years of service do you expect to get out of them?


John

 

1964/78 FT's use a similar engine mounting system as 1961/64 F100/700 292.

Front: 2 rubber insulators, 1 upper and 1 lower. L shaped bracket bolts to front of engine, has one rubber insulator below the crossmember, one above the crossmember. Bolt passes thru bracket, upper and lower insulators. Nut and washers to bolt.

Rear: 4 rubber insulators, 2 upper and 2 lower. Bell housing has 2 "ears." One rubber insulator below cross member, one above cross member below ears. Bolt passes thru lower/upper insulators, ears, nut and washers to bolt.

FT's use different head gaskets and flywheels than FE's. In fact, most of the parts are FT only.

 

Those PI motors are worth a few bucks if rebuidable. If not some of the parts are.

 

Yes, you can, it would give you a 410. The 410 and 428 cranks are the same stroke if not the exact same crank.

Sounds like you want to put one of these in a car or small truck?

If so, take one of your 361/391 blocks, bore it out enough to clean it up, slap a 410 or 428 crank in it (with the right flywheel and balancer) and a set of FE heads (not 361/391), intake and whatever and call it good.

I don't know if 391 rods can be used in an FE motor, but I suspect they can, but might be beefier.

I would certainly suggest getting the motor balanced once you figure out what you want to make

 

You will also need a bushing for the distributer in the block to put a passenger car dist. in it and the timing cover from a passenger car.


If you are wanting to stroke the engine and put it back in the truck it came from, the crankshaft snout on passenger engines is smaller dia and will not fit the timing cover (I think) and the damper/pulley (Im sure)

 

I think the following is true:


A real 410 crank with casting mark "1U" is internally balanced and can use same balancer and flywheel/flexplate as 390 and other int. bal. engines


A 428 crank with casting number of "1UB" or "1UA" requires the external bal. damper and flywheel/flexplate. The "1UA" also requires the "hatchet" spacer. This is the Super Cobra Jet crank

 

428 with #1UB crankshaft uses the same harmonic balancer as 1968/70 390 Passenger Cars and 1968/76 F100/350 360/390.

D5TZ-6316-D (replaced D2TZ-6316-A & C8AZ-6316-B) .. Harmonic Balancer Assy.

S/CJ crankshaft is either #1UA (1969 before 12/26/1968) or #B (1969 from 12/26/1968 & 1970).