390 Truck engine same as car engine.
Senior User
Joined: Dec 2002
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From: Port Angeles WA
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.
FE "Freakin Expensive"
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From: Smith Mountain Lake, VA
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
Cargo Master
Joined: Aug 2000
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From: SW Michigan
truck vs car
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
Post Fiend
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From: Missouri
Originally Posted by bchitwood73
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.
Post Fiend
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From: Missouri
Originally Posted by RapidRuss
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
FE "Freakin Expensive"
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From: Smith Mountain Lake, VA
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From: Long Island USA
Originally Posted by dinosaurfan
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
One motor had 10.5:1 in the 60's, (GT?) but probably was in the Ranchero only...
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Hotshot
Joined: May 2003
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From: south louisiana
Originally Posted by krewat
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...
One motor had 10.5:1 in the 60's, (GT?) but probably was in the Ranchero only...
Logistics Pro
Joined: Feb 2000
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From: Sun River St. George
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.
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From: Long Island USA
Originally Posted by baddad457
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.
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).
Post Fiend
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From: Brea CA
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.
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From: south louisiana
Originally Posted by Purely Ford
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.
