Are there any differences between a 390 truck engine and a 390 car engine?
Like: crank, etc...

Thanks, Duane.

 

Not sure about the internal differences but 390 truck heads will have top to bottom bolt holes for the exhaust manifolds where car heads will be the traditional side to side I am pretty sure.

 

If my memory is right? The Engines in the cars had a slightly warmer cam and had a higher compression.. And I do believe after 70? the cam in the truck was slightly retarded from the factory..One of the Guru's will correct me if im wrong!LOL!-Russ

 

Most of the pickup truck 390s were equipped with very low compression pistons. Less than 8 to 1. The good news is that you can use car style pistons when you re-build and get better performance. DF

 

The only car heads that had different bolt patterns than the truck was some of the HP versions. They had 14 - 16 bolts instead of 8. Most car heads and truck heads were the same. Even in performance.

 

1972 was the year I believe. They were retarded 8 degrees.

 

Rat, Thanks for clearing that up for me..I couldnt remember if it was 71 or 72?-Russ

 

Not correct, at least according to my trusty Motor's Truck Repair Manual (1979). It lists the 390 as having 8.6:1 compression from 1968 until 1972, when it went down to 8.2:1

One motor had 10.5:1 in the 60's, (GT?) but probably was in the Ranchero only...

 

The pistons will have 2V or 4V cast into them. I am sure the compression ratios were relatively higher in 4V engines than 2V engines.

 

The 10.5 to 1 390's also came in both 2 bbl and 4 bbl form, in GT and non GT versions. And were installed in just about every Ford and Mercury car line. Stangs, Fairlanes,Galaxies,Montereys,Cyclones,Torinos,etc. The 68 Merc Monterey I have came with a 10.5 to 1 2 bbl 390. Had a 68 Galaxie parts car that was built a week before the Merc that had a 9.5 to 1 2 bbl 390.

 

Buy Steve Christs book "How to Rebuild Big Block Fords", available here at Motorhaven. There are other books but this one is really good, easy to read and has enough pertinent facts so that anyone can build one of these motors. I like later truck blocks, they have enough bolt holes for the motor mounts, include all the later run improvements and were made by the millions. Hard to screw up an FE and if you do there are plenty more available.

 

Just to be clear, I was talking about trucks only... Only 1969 had a S-code 4bbl 10.5:1. By no means is this book 100% accurate, but generally, it's believable. I haven't seen any glaring misinformation in it, compared with info from this and other sites.

So, apparently, except for the rare (or not) Ranchero with a 390GT 4bbl, yes, truck motors were different than the car motors, but only in the compression (and maybe cam or cam timing).

 

Baddad, did you notice if the pistons had 2V or 4V cast into them . I am dead on the money that 2V and 4V pistons changed the compression ratios in any FE.

 

The 390 truck engines used the 410 piston and the 410 is prominantly stamped on them. Passenger car 390 pistons, 2V or 4V, are 1.76 or therabouts compression height (the 390 4Vs being also used in the truck 360s), 410s and truck 390s are 1.66. That's how they lowered compression in trucks without stocking new pistons.

 

I've still got an extra set of the cast flat-tops it came with, well sort of. A local auto machine shop gave me a full set of cast flat-tops that were identical to the ones in my Merc. The 2 bbl motors got dished pistons, the 4bbl and high comp 2 bbl's got true flat-tops. Engine code in the Merc is for a 10.5 to 1 ratio 2 bbl motor. And for you BB, not all 390's with 410 pistons were 390's. I had a 70 F100 with one such "390" . Sure it had 410 pistons, but also had a 410 crank to boot. Never know what you'll find in an FE that was assembled by Ford.