New Engine for My '76

[Chevy1966]

I'm looking for ideas and advice on an engine upgrade. The 350 in my '76 3/4 ton 2WD is run out and I would like to replace it with a new engine. I am willing to spend some $$ and would naturally like to maximize fuel efficiency, but I am not sure what options are worth considering. Just looking for some help from those that have more knowledge and experience than I do. Thanks!

[Want2Run]

You're looking for fuel efficiency in the motor?

[Chevy1966]

Yes, I would like to improve the gas mileage, but I don't want to give up too much power. I was thinking that a later model engine might be more efficient. Maybe with fuel injection?

[king-918]

Ls is the way of the future
Posted via Mobile Device

[nheller76]

U will have fun wireing up a fuel injection motor! U can do other things to the drive train to.make it more fuel efficient! 350's in general were ment to be powerhouses. And being an owner of a 3/4 tone truck myself the rear is not geared for gas mileage. U might be better off getting another gas saver and building your truck up.as a toy. Not saying u can't do it if u switch your running gear out for 1/2 tone stuff and see if u can get a 700r4 or even switch to.a stick u may get better mileage there.
Posted via Mobile Device

[Want2Run]

Originally Posted by Chevy1966

Yes, I would like to improve the gas mileage, but I don't want to give up too much power. I was thinking that a later model engine might be more efficient. Maybe with fuel injection?

If you're looking to go fuel injected, holley sells an atomic EFI kit seems fairly simple but rather pricey, it hooks up to carbureted motor. Take a look at that see if that is something you may find interest in, not sure about fuel mileage on it but theoretically it'd help. That or he has a point 350 were made for power.. also rear en gear has a lot to do with it.

[Chevy1966]

This is all great info... thanks! I was not familiar with the LS engine but reading up on this now. As for fuel injection I realize this would be a project - not sure if the outcome would be worth the effort & money - just trying to learn from the experience of those that have been down this path and understand what would be involved. The easy answer would be to buy a newer, fuel efficient vehicle, but I love my old truck and love driving it! Again, thanks for the feedback.

[LynnJr]

http://www.lt1swap.com/

[Blackpony]

an ls swap is the best way to go imo. with a th350 trans and 3.08 gears, I regularly knock down 19-20 mph hwy with the a/c on blast! once i get a 4l60 trans in there, it should pick up 2-3 mpg. the best part is it makes 340 rwhp and drives like stock!

[Ziegelsteinfaust]

He has a 76 and it needs to be smogged or he'll have to go through a referee station.

If I was building a smogger I would use standard sbc heads with a 170-180cc head. A modern cam from your favorite cam supplier, roller rockers, full bolt-ons, and a T700R4 or 4L60 for the overdrive. The I would replace your 10.5 14 bolt with the 9.5 14bolt with 3.42 or 3.73 gears. It weighs almost 300 pounds less, and with the gear change will help alot towards better mpg.

I got myself a 74 C20 to avoid the smog nazi's, and I am likely to do a 350 Vortec for my transplant.

[totos956]

Originally Posted by Blackpony

an ls swap is the best way to go imo. with a th350 trans and 3.08 gears, I regularly knock down 19-20 mph hwy with the a/c on blast! once i get a 4l60 trans in there, it should pick up 2-3 mpg. the best part is it makes 340 rwhp and drives like stock!

I'm with u on that one
I got an ls swap on my and she's good on gas and hauls A$$
Posted via Mobile Device

[INSIDIOUS '86]

Surprised nobody has mentioned tpi. But being that you have a non exempt smog truck your mods will be limited.

In a nutshell power takes fuel so that means you need to make it put that power down efficiently. I don't know if you have an overdrive trans but that will make the biggest difference. Getting the cam intake and heads to match to where they make peak torque at an rpm that you normally cruise in. Peak torque is where your engine is most efficient in making power and burning fuel the lower in rpm this is the better...to a point making this at about 2500rpm is optimal so keep your rear gearing tailored to keep in that rpm at highway speeds. Good tires help too and making the truck lighter overall.
Carb vs efi a carb CAN be tuned to outperform efi but this takes work and dedication that is usually seen in high dollar racing. And that tune works good for that days weather but back to back and some decent tuning that takes some knowledge both are comparable. The advantage that efi has is its constantly tuning and keeps your engine tuned at peak this makes them all around efficient. A tpi Intake makes a great torque band and can be run off the smoother and quicker computing ls computers.

My suggestion...just find an engine that will make some good power and pass smog. Of you don't have an overdrive trans now is a good time to add one. It will prob make the difference of being decently alright filling the tank at the fuel station or trying to decide if you want bacon in the morning or gas
Posted via Mobile Device