good or better engine/trans build/swap for better mpg 82 C10 305/metric trans

[ken.walker.1806]

I wound up with a nice old '82 C10 Silverado with 92k one owner miles after my son made off with my new:er truck. The '82 is a nice looking truck but the engine is a very tired 305 with a metric transmission and the gas mileage is awful, my other truck got 21-23 mpg average and about 14-17 mpg pulling a loaded car trailer, it had 5.2 and a 5 speed. I have owned Chevy's before and I have got real decent mileage on 283s and 327s but the 2 trucks with 350s got such bad mileage that I switched brands. I have talked with several people and read as much as I could as to why the 350 hogs gas such as they do and heard that bad flowing heads, restrictive exhaust ,bad cam specs and transmission type are to blame. If this is true what block,heads and cam would be optimum ? I want to stay with an automatic transmission and use fuel injection instead of carburetor   I plan to do mostly highway driving and pull my car trailer loaded with my '41 Ford coupe at showtime. I am an old racer that understands how to make em go faster and get awful mileage but I guess I missed the one on going the speed limit and better mileage. I have a budget of $2500 and hope to find 18-20 mpg if anyone thinks it's possible. If not anyone want a nice.....

[dvdswan]

IMO go with a LS engine. 

[Rich84]

Tuned Port Injection is an inexpensive way to get the benefits of fuel injection at a reasonable price. It is old technology, but it is very dependable and easy to work on. I average about 20 mpg with very little highway driving. The lb9 has plenty of torque and makes a real nice truck motor.

[Captkaos]

Get a pull out 4.8L or 5.3L LS motor.  18-20 mpg isn't out of the question for a TBI 350/700R4 though.

[ken.walker.1806]

Hey thanks guys, I guess I'll see what my local salvage yards have to offer.

[DuckAholic1]

Get a pull out 4.8L or 5.3L LS motor.  18-20 mpg isn't out of the question for a TBI 350/700R4 though.

Hey Captkaos,I don't mean to high jack this  topic, but I sure would like to know some tricks/ideas on how to get 18-20 mpg with my 87 TBI!! I think I am getting 12-14 now. Just rebuilt TBI, w/no difference in MPG. Also new 700r4 Tranny. Maybe you could shoot me a PM or Start new topic. Love hearing what you and others have to say, As I continue to learn from this site. Thanks 

[Captkaos]

what setup are you running? trans? rear gearing?  Tire size?
What speed are you getting this mpg?  Highway or town?
If around town in a lot of stop/go that sounds reasonable. If it is highway not so much.  And by 18-20 I was talking highway mileage.  My 87R10 prior to the trans puking got 17/22 constantly.  It was a 305/700R4 with stock size tires and 2.73 gears.  highway speeds were around 62-65.