HI everyone, hope the New Year is great for everyone.
I have a 51 C cab that I have had for some 32 years. I drive it nearly daily, and it has around 650,000 miles on it.
When I got it there was a 232 V8 sitting in it that the original owners son said the dealer had installed.
It now has a 62' 289 in it with a 3spd/OD transmission and a 4:11 rear end (Ford 8"). It is running on a set of 16" truck radial tires.
The carb is a Holly 2 barrell that was a stock unit for either a Chevy
283 or Ford 289, can't remember which, not that it matters what it was supposed to fit. It has a manual choke.I am running stock distributor and the system was converted to 12V. Engine compression is good, even in all cylinders, but the exhaust and plugs always look a little black.
When driving in a reasonable manner, trying to be sensitive to fuel economy, I can get about 10MPG city and 13 MPG on the highway traveling at speeds in the 65 MPH range.
If I am pulling my motorcycle trailer or have a couple of my bikes in the back (I collect early Japanese bikes, pre-1959 and slightly later) the MPG drops to about 10 on the highway and less in city or congested traffic.
This just does not seem right to me and after years of complaining about it, I thought the collective minds in the group might have some thoughts.
I have a 4 barrell manifold and several friends have told me to put an Edelbrock 500 CFM 4-barrell on it, claiming that my carb is probably junk, and that the smaller primary barrells in the Edelbrock will give me better city fuel consumption as long as I keep my foot out of the secondaries.
Others have recommended an electronic ignition conversion for the distributor and a hotter coil in addition to a new 2-barrel or the Edelbrock.
The exhaust is a single unit, that has some years on it but seems to be flowing OK. I found a sticking manifold heat valve 6 months ago, replaced it thinking that it could be contributing to poor overall performance, but it had little to no effect on the fuel economy. I had thought of converting to a dual exhaust, but have some routing problems due to the second stock fuel tank that I installed on the passenger side (during the fuel crisis in the 70s').
SO.....my question to the group has several parts: Should I expect better fuel economy? What should I check or do that I have not done? Thoughts on the 2-barrell vs. 4-barrell?
I have thought about a gear ratio change since the OD transmission allows me to accelerate from a stop easily even with a load and perhaps dropping the engine RPM at cruising speed would help, but so far, the only way I have found to get better mileage is shutting it off........
Thanks! Allen