Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Project 1977 F100

dieselattempter · 12-07-2012, 01:38 AM

i have had quite a few 73-79 fords all owned in my lead foot phase. the best i mpg i could get constantly was 1977 f100 swb 302 4 speed 17mpg highway. the first thing is a good tune. your truck need three things in order to run well fuel air and spark

air is easy you either have it or you don't, there are many manifolds that flow better or worse,but for now fuel and spark are key.

having a properly set dist, is gold but what even seasoned techs forget is (not doubting your guy but just adding food for thought) factory settings aren't always best for your fuel type/driving style and engine age. you can run your timing more advanced on higher octane fuel, without detonation. the idea is to get your spark in the window of peak efficiency and power. run a slightly larger gap, use a later model dist and ignition control box.

fuel... i am not so familiar with fords an lpg, not saying its bad, i just dont know em. but for gas carbs, mine loved to leak at the base gasket and egr, usually i tossed the egr and liquid gasketed the base. not the best solution but it worked. i have even swapped 2 barrel carbs to 4 barrels an gotten performance and economy. usually the primary barrels are smaller on 4v carbs so if you are light on the foot you can use less gas.

as far as your tranny/diff woes i have played the same game but through time learned to do my own research and find out what works. for a long time ford used two v8 bolt patterns small block and big block. most common are sb=289/302/351 bb=351/400/460(plus diesels) i know that australia got a de-stroked 351 aka 302c i am not sure if you guys got any other goofy engines. but look for 5 speeds in any ford truck 80-97ish and do a little reasearch and see if the input shaft is the same length. the trans might be a lil longer but if its cheep enough you take the drive shaft too. i was told by a shop that there was no way that any c6 would fit in a 77 f100 302 that had a c4. pulled one out of an 86 f150 5.8l bolted in on and moved the braked to the "c6" bolt holes and drove it for two years.

diffs are even easier find one out of any ford truck (just make sure it has the right lug pattern).if it has the ratios you want seat it. you might need to do minor fab work on brackets but you seem to be up to it.

i guess i ranted there but my point in the end is always look and think outside the box. trucks are easy they only have a few parts and 99% of them are interchangeable within 50 model years of each other.

if you were in the us i could probably find you a free trans and diff

good luck and boss truck!

12-07-2012, 01:38 AM	#137 (permalink)
dieselattempter EcoModding Lurker Join Date: Dec 2012 Location: rochester,wa Posts: 2 the jetta - '86 volkswagon jetta 90 day: 45 mpg (US) the bike - '71 honda cb450 Thanks: 0 Thanked 1 Time in 1 Post	ford tips i have had quite a few 73-79 fords all owned in my lead foot phase. the best i mpg i could get constantly was 1977 f100 swb 302 4 speed 17mpg highway. the first thing is a good tune. your truck need three things in order to run well fuel air and spark air is easy you either have it or you don't, there are many manifolds that flow better or worse,but for now fuel and spark are key. having a properly set dist, is gold but what even seasoned techs forget is (not doubting your guy but just adding food for thought) factory settings aren't always best for your fuel type/driving style and engine age. you can run your timing more advanced on higher octane fuel, without detonation. the idea is to get your spark in the window of peak efficiency and power. run a slightly larger gap, use a later model dist and ignition control box. fuel... i am not so familiar with fords an lpg, not saying its bad, i just dont know em. but for gas carbs, mine loved to leak at the base gasket and egr, usually i tossed the egr and liquid gasketed the base. not the best solution but it worked. i have even swapped 2 barrel carbs to 4 barrels an gotten performance and economy. usually the primary barrels are smaller on 4v carbs so if you are light on the foot you can use less gas. as far as your tranny/diff woes i have played the same game but through time learned to do my own research and find out what works. for a long time ford used two v8 bolt patterns small block and big block. most common are sb=289/302/351 bb=351/400/460(plus diesels) i know that australia got a de-stroked 351 aka 302c i am not sure if you guys got any other goofy engines. but look for 5 speeds in any ford truck 80-97ish and do a little reasearch and see if the input shaft is the same length. the trans might be a lil longer but if its cheep enough you take the drive shaft too. i was told by a shop that there was no way that any c6 would fit in a 77 f100 302 that had a c4. pulled one out of an 86 f150 5.8l bolted in on and moved the braked to the "c6" bolt holes and drove it for two years. diffs are even easier find one out of any ford truck (just make sure it has the right lug pattern).if it has the ratios you want seat it. you might need to do minor fab work on brackets but you seem to be up to it. i guess i ranted there but my point in the end is always look and think outside the box. trucks are easy they only have a few parts and 99% of them are interchangeable within 50 model years of each other. if you were in the us i could probably find you a free trans and diff good luck and boss truck!