Hi Everyone. I have a 1976 391 FT engine. I recently did a perk up on a 390. (Cam, 4bbl intake/carb, all that good stuff) The specs on the 4bbl intake (eddybrock) for my 390 said that it will not fit the FT engines. What is the reason for this? Somebody told me that the heads are different on the 391 and thats why it won't fit. But the heads on my 391 are the same as my 390, D2TEAA. Were these heads stock on 391s? Is there any possible way of fitting an aftermarket 4bbl intake on a 391 engine? Is there a way of kind of transferring parts from an FE to an FE to make certain components work? I have a spare 360 for parts I could use if this was possilbe. Also what made these engine such low compression? Was it the heads, pistons or both. I am just curious about that question. I am not looking to build it up a lot just to perk it up for a farm truck I have at home. I am planning on putting an RV Torque cam and a roller timing chain set and advancing the cam 4* with the crank gear keyway and if also possible, a 4bbl carb. Fe cams will fit FTs right? Also, are there any problems with my plan? Thanks again for helping guys, your input is greatly appreciated.

 

Sorry I meant transferring fe parts to an ft engine.

 

Heads are different on the 391. Smaller ports, and different exhaust crossover. Smaller valves, maybe too, don't remember

I think the compression is both the pistons and the heads. If you were to bolt on FE heads and intake (take care of the distributor hole size mismatch) and exhaust manifolds, the compression would probably come up a little bit.

Is your 391 a 2 bbl? there were 4 bbl intakes for FT's, but who knows how much of an improvement that would be with those heads.

Also, I'd wonder if the FE cam has the same distributor drive gear on it as an FT. Guys?

For a real wake-up, get FE heads (C8AE or D2TE), freshen them up, get a 4bbl intake and exhaust manifolds. The distributor hole in the intake for the FE is smaller, so you'd need an FE distributor, but with the FT drive gear on the end (hole in the block where the gear goes is bigger on the FT's) I believe.

I think.

Guys?

 

I understand what you are saying Krewat, but the heads I have on my 390 have exactly the same casting numbers as on my 391 which have a 203 and D2TEAA stamped on them. It does appear that the engine has been taken apart some time before because of excess silicone coming out of places where gaskets were put in. Yes this engine is a 2 barrel and the intake manifold cast number is D5TE-9425-KB. Can someone verify if this is a 391 for sure? It has the block casting D4TE on it which is an FT. Is it possible someone could have just used this block and swapped FE parts onto it? Oh ya the timing cover is also cast iron if that also helps.

 

And I just thought the 391 collecting dust in my garage only had extra webbingfor the crank journals.... I'm pretty sure that FE parts will fit an FT block, but now that you mentioned the different drive gear Krewat, I wonder if I can get one from Isky? I will be running a .542 lift, 270 duration cam, PI heads (I think they're C2AE) and OEM aluminum PI intake. Even got a OEM PI 4bbl, but may swap it for an Edlebrock....

 

I THINK that the hole the end of the drive gear fits into is a different size for an FT. And, the oil pump shaft is different too, I think.

I remember reading that here, so if it's not true, it's someone else's fault

 

391's had sodium exhaust valves and rotators as original. I have yet to see any FE engine with those features. The parts catalog lists different part numbers for 391 cylinder heads and gaskets as compared to FE's.

 

so does this mean that the d2teaa heads are'nt original on the 391 considering they are the same exact heads as my 390?

 

Hard to say. You'd need to compare the date codes of the block, head and intake and see how close they are. I suspect the heads might have the FT center crossover and could possibly have the same D2TE casting number....or have been changed at some point. Does your intake have the heat crossover in the middle or towards the rear? It could be a 391FT shortblock and someone put FE heads and intake on it if the crossover is towards the rear like FE's.

G.

 

I wouldn't think the D2TE-AA heads are original, if they are on top of a 391. Key point being, IS it a 391?

I don't have valve specs on the FT's vs. the FE's, anyone out there got something to add to this? PLEASE?!?!!?

 

We show the 391 motor uses an FE distributor, but with a Cleveland gear.

 

The 391 head may look the same as a FE, they may even be the same raw casting, but have different valves/springs/head gaskets. A quick look in the parts catalog shows the same valve cover gaskets, the same valve seals, the same pushrods 391/FE.

Cast numbers on blocks/heads should be taken with a grain of salt. The FE 352/360/390's all have "352" cast on the block...but are all the engines 352's? No.

 

I was thinking they could be FT heads with the D2 casting number. Generic numbers sorta like the blocks. If they have the center crossover and the D2 casting number it might jive. For FT heads I don't have any 70's part or casting numbers. Only the 60's stuff. I bet Bill has them tho and I'd like to know it as well. The 391 FT C4TE-6909-A heads used a 1.5 ex and 1.745 in valves with 78-81 cc chambers. If the heads have the FE heat crossover they are FE heads that have been swapped. I bet that's the case.

G.

 

what do you guys mean by the heat crossover?

 

1964/72 Ford Truck Parts Catalog

1968/72 Cylinder head part numbers

391 = C4TZ-6049-E .. Cyl Head-w/o valves / D2TZ-6049-D .. Cyl head-with valves

FE = C8AZ-6049-M .. Cyl Head-w/o valves / D2TZ-6049-E .. Cyl Head-with valves

Note that both FE & FT engines have heads with D2TZ prefixes, but that doesn't mean the heads are the same. All that D2TZ refers to is 1972. The heads with valves have updated part numbers (typical of Ford).


Note that the both the FE and 391 heads without valves retain there original part numbers from the years the engines were first introduced.


FT 330/361/391 engines introduced in 1964 (C4), 360/390 introduced in F Series trucks in 1968 (C8).

C: decade = 1960's; D: decade = 1970's. Next number is the year; T is truck; the Z means nothing, it's there for phonetic reasons only.