302 vs 390
Cargo Master
Joined: Oct 2011
Posts: 2,242
Likes: 299
From: Kenner,La.
302-390
Sir , the only subsitute for cubic inches is cubic dollars, I would also change the ignition to Duraspark and if you can afford it a throttle body fuel injection,a matching aluminum manifold ,headers along with a TKO and gears that was already posted.Kenny Nunez
Senior User
Joined: May 2010
Posts: 307
Likes: 1
From: McMinnville, TN
A 390 will pass anything on the road...except a gas station!
I have a 302 in my 85 and it's done well for many years, but it lacks the grunt to really use it like a truck. Garbage, light loads, sure. Pulling or passing...so,so.
I have a 302 in my 85 and it's done well for many years, but it lacks the grunt to really use it like a truck. Garbage, light loads, sure. Pulling or passing...so,so.
Senior User
Joined: Dec 2001
Posts: 105
Likes: 0
See my sig, I just went from a 302 to a 390...I'm getting BETTER mileage with the big motor (RV cam, performer, longtubes) simply because I don't have to mat the pedal, EVER. The 390 just idles along, got 13mpg yesterday at 70mph on a 90 mile trip. I towed 5,000lbs frequently last year and had to floor it just to beat strong headwinds and little hills. Was lucky to get 7mpg out of the 302 then. I posted this somewhere before, but here's my setup and tune again:
Edelbrock 1404, 500CFM:
Jets, .086/.095
Nozzle, .28
Springs, Pink
Metering Rods, 65x47
Performer Intake
2 1/2" x 14" Air Cleaner
Hyd. Flat Tappet Cam (Melling MTF-4):
204/214 @ .050
.486/.512 Lift
104/120 Lobe Ctr.
107 Lobe Sep.
Hedman Headers
Dual 2 1/4" Exhaust, Behind Tire Exit
Delta Flow Mufflers
OEM 1974 Breakerless Electronic Ignition
11 Degrees Initial, 36 Degrees Total Timing
Autolite 45 .036 Gap
C6 Auto
Stock Converter
3.00:1 Rear Gear
31" Tire
Edelbrock 1404, 500CFM:
Jets, .086/.095
Nozzle, .28
Springs, Pink
Metering Rods, 65x47
Performer Intake
2 1/2" x 14" Air Cleaner
Hyd. Flat Tappet Cam (Melling MTF-4):
204/214 @ .050
.486/.512 Lift
104/120 Lobe Ctr.
107 Lobe Sep.
Hedman Headers
Dual 2 1/4" Exhaust, Behind Tire Exit
Delta Flow Mufflers
OEM 1974 Breakerless Electronic Ignition
11 Degrees Initial, 36 Degrees Total Timing
Autolite 45 .036 Gap
C6 Auto
Stock Converter
3.00:1 Rear Gear
31" Tire
Posting Guru
Joined: May 2010
Posts: 1,867
Likes: 3
From: Alton, MO
I currently have a 302 in my SWB '70. She is plenty quick. I think the smaller displacement is compensated for with less weight. Mileage is between poor and downright rotten. I also do not use my truck as a truck. It is a toy. I am putting in a 460/C6 after the 1st of the year. I would also have to question what your plans are for the truck. The higher the truck sits the heavier engine will affect handling more in a negative way than the lighter engine will. Depending on front springs the heavier engine can cause the truck to "plow" into corners.
For quick, better handling I would go with the 302. Brute force the FE. FE's can also be quick. I would not expect any difference in mileage between the two. If anything I would expect the FE to get better mileage given all other factors identical. As stated in an earlier post you simply do not need as much throttle.
For quick, better handling I would go with the 302. Brute force the FE. FE's can also be quick. I would not expect any difference in mileage between the two. If anything I would expect the FE to get better mileage given all other factors identical. As stated in an earlier post you simply do not need as much throttle.
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1967 - 1972 F-100 & Larger F-Series Trucks
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