what is the power difference between the 390 and a 460?
the 390 I have I want to rebuild but it seems better to just drop in a 460?
any views on this would be appreciated,
e-mail me @ thefireman4652(No Email Addresses In Posts!)
thanks James

 

I debated this same issue and stuck with the FE, mainly because it is original. An FE can make awesome power as can a 460, so the choice is really personal. Also, I didn't want to screw with new perches, tranny, etc.

 

This has been debated many times, check the FE forum for some good info.

Money wise, it can be a toss up. the 460 motors and parts are a bit cheaper, but you'll have to change motor mounts, maybe the tranny or bell-housing and any accessory brackets.

There are quite a few parts available for FE engines and a mild street build up is not the expensive.


FYI, there are FE combinations to get over 500 Cubic inches. These take money, but are availabe. I'm awaiting my 446 FE motor to arrive, hopefully within about 2 weeks.

Again, check the FE forum.

 

Depends if MPG is any concern. I never knew anyone with a 460 that got anything other than 8 mpg. With a 390 at least you have a hope of 12 mpg. Other than that and the cost of conversion, I would not place one over the other.

You might find it easier to convert a 460 into a 4x4 than a 390 because there are tons of 460 4x4 trucks around.

EFI is a lot easier for a 460 than a 390.

 

thank you all for your input, know the quistion is I have just gotten new rings rod bearings and oil pump, can't afford the price of a engine overhaul but hope this will cure my lower end and low compression problem.
next.. is there aluminum intakes that are within' the means of my pocket book..summit has the chepest edlbrock maifolds I have found.
my wife and I would love to get the maximum power and reformance from this 390 because of the job we have and the amount of weight we put in the back of it plus the trailer.

I was quoted $1,071. for a total rebuild can I do it for less?
Thanks for the input.

James and Donna
thefireman4652(No Email Addresses In Posts!)

 

If you go for cheap on the rebuild, you will get what you pay for. Any time you start changing anything around on a Ford all kinds of strange little things crop up, so expect to spend a lot of time chasing down brackets and such. I wouldn't do the swap unless I had the complete doner vehicle for this reason. The 390 doesn't need much to outpull a stock 460. Used manifolds are hard to come by so expect to pony up the 275 or so for a new dual plane. Offenhauser still offers one through Summit. Have your machine shop reccomend a good cam for you transmission/ gear ratio and for the use intended. Keep in mind that every one you ask will have a different preference. Or you could just pick a manufacturer and call their tec line. I have had good luck with Comp Cams. Headers will really wake up the 390, but buy good ones and expect some upkeep like ocassional gasket replacement. Just remember that the newest of these engines are nearly 30 years old and over the counter parts for the 460 are more plentiful. also make sure your cylinder heads have hard valve seats and new guides with posative valve seals and not the original umbrella style seals. If you go with the 390, get the later electronic ignition and ditch the old points distributor. Good luck

 

Thanks willowbilly3,
That is some good info, I have been so used to working on mopar that the ford is a little harder then I thought.
we will take your advice and put into this truck.
agean thank you
James and Donna

 

There is lots of parts that won't cost you much that will help perf on 390 if you aren't going to tear into interior engine parts. Upgrade dist, headers, K&N air filter, new plug wires, carb, and manifold. I believe Edelbrock manifold cost me $240 at Jegs.com. You won't believe how heavy that stock mani is, have someone help you carry it. I used a Comp cam #260, and with Flowmasters it has just a little bit of a rough idle, but sounds great.

 

You can buy a complete EFI 460 from a junkyard for under $700. The C6 (3 spd. auto)will run you 150 and a ZF(6spd DOD manual) will be 125. You can do it. The 460 weighs in at 760 lbs. so you better have some heavy lifting equipment. You could keep the 390 for originality, but a 460 will kick its *** hands down. You might get 8 MPG tops, the 390 I have with a 3 spd OD toploader gets 15 on the highway and 8 around town. Those are pretty god numbers for a 40 year motor.

 

baitmaster is right on, I use a cherry picker for those manifold swaps nowdays. I did the swap to a cast iron 4 barrel on an old highboy when I was younger and said never again with out a lift.
mattsbox, if that isn't a typo I would like to know where to get the 6spd for 125. Also have you done this installation? If so how did you deal with the hydralic cluch issue.

 

This is just one example and nothing that is carved in stone but about 20 years ago I built a 75 F-250 4x4 for my brother in law to use on the ranch. I got a used 390 and reringed it. The truck was a 4spd with 4:10 gears. They also had an early 80s F-250 2wd supercab with a 460 and manual trans, I think it was a granny gear 4 spd also. Both engines were stock except the 390 had dual exhaust. He always said that 390 would outpull the 460 big time. It was a very strong 390 and a rather lackluster 460 but it still happened. By the way they still have the 75 (blue thunder) , the reringed 390 is still going strong and it's been to the edge of hell and back more than once

 

Well I got to the guts of my 390 and found that the crank is broke in two, right at the front 2 cylinders, now I could get it dipped and line bored but my problem is that if it did it this time what 2 say it won't agean? should I just get a wreaking yard motor with the crank and put my heads and intake on it and all my new parts or return my parts and get a long block motor?
problem is is time have very little with our job.
please help

James and Donna

 

Willowbilly3, I never did the ZF swap, but there are a lot of dodge trucks in the junkyards up here so they are quite plentiful.

 

Wow fireman, I don't think I ever saw a 390 break the crank. If you can find a good wrecking yard motor, or a trustworthy wrecking yard with a good reputation, Then that would be my pick for low budget. The last time I needed an engine build, I had a custom engine builder do it and never have regretted the extra money it cost. Be careful buying a 390 since you can't tell a 360 from a 390 without pulling the heads or pan and measuring the stroke. There have been a lot of 360s pawned off as 390s. Stay away from the early 390 since it won't have the motor mount bosses that you need cast in the block. I have used the older block but it required a lot of fabrication on the moter mounts. Now is a good time to make sure you have hard valve seats. I destroyed a 300-6 head in 25,000 miles that didn't have them
If you have your old block checked it should be ok. The crank broke because it had a real hard life no doubt. It may have done duty in a race car or something or maybe the engine was in a bad head on accident. It sounds like you need to find a good machine shop. Try to find one with a ford lover working there. Anyone can work on a chevy, it takes a real mechanic to work on a Ford

 

I don't know 99, it seems to me there are a lot more chebbys in the Billings junkyards then anything..JMO..