Almost 40 mpg in my 1966 Chevelle !!!

[67-ls1]

Originally Posted by cRiPpLe_rOoStEr

It doesn't seem to have really been an issue. Just to remind, the Corvette C6 and C7 had a transaxle based on the same 6L80 fitted to the 5th-gen Camaro when equipped with a V8. I'm just not so sure about the possibility to fit 6L50 internals on the casing of a Corvette-spec 6L80.

I would venture a guess that a C6 or 7 transaxle cost multiple times more than I paid for my complete engine/trans/ECM/harness package with only 525 miles on it. These V6 engines are not in the “LS” price range.

And while I did have to build motor mounts and reshape/rebuild the K member, adapting a transaxle would have been beyond my capabilities.

[cRiPpLe_rOoStEr]

Originally Posted by 67-ls1

I would venture a guess that a C6 or 7 transaxle cost multiple times more than I paid for my complete engine/trans/ECM/harness package with only 525 miles on it.

Everything seems to be more expensive when it comes to Corvette stuff.

[ALS]

You'd be amazed at what many of these older cars can get. I went to a Pontiac Oakland Convention in the early eighties. I had a 1965 GTO Convertible with a stock 389ci, 3X2 bbl carburetor set up, four speed and 3.90 rear gears. BTW that center 2 bbl carb was pretty small compared to the end units. It wasn't that bad on gas as long as you didn't open up the other two fuel dumps. It had the aerodynamics of a cinder block, weighed around 3,500lbs and rolling on Bias-ply tires.

I got a hair over 19 mpg on my way up and back with the top down at 55 mph. I always wondered what I could have gotten with say 3.08 or even 2.73 rear gears in that car on the highway.

My buddy was working at a Chevy dealer at the time and drove his take home car a brand new 81 Z/28 automatic to the convention. He barely got 17 mpg on the exact same trip running the speed limit of 55 mph.

[Bilster]

Beautiful! I’ve got a 1966 El Camino. Your build really inspires. Who did the engine harness?

[67-ls1]

Originally Posted by Bilster

Beautiful! I’ve got a 1966 El Camino. Your build really inspires. Who did the engine harness?

It’s the factory harness out of the Camaro. I had a guy in NY modify the harness and ECM for my application. I would do the harness myself if I had to do it again. And I’d have the ECM done closer to home because it’s been UPS’d back and forth across the USA way too many times.

[Ecky]

Alright, I'm impressed. This is a cool project and your results are outstanding.

A word of skepticism - I tend not to be very trusting of short fills, even if it's to the point of spillage. But even if it's 2-3mpg off (or more) those are still outstanding numbers.

[67-ls1]

Originally Posted by Ecky

Alright, I'm impressed. This is a cool project and your results are outstanding.

A word of skepticism - I tend not to be very trusting of short fills, even if it's to the point of spillage. But even if it's 2-3mpg off (or more) those are still outstanding numbers.

Yeah, me too. It was 90+% highway at 60-65 mph. And the purpose of the trip was to maximize the mpg, so I drove like there was an egg under my throttle foot.

I have been getting 30-32 on full fill ups driving it as my daily driver, still more highway than in town.

I’ll do another all out mpg run of a greater distance soon.

[mattrod]

That's quite impressive. Nice work.

[MeteorGray]

Outstanding performance! Congratulations!

And that car is beautiful. It reminds me of a '63 Pontiac Tempest I had. It was powered by a 326CID V8, if I remember correctly, with a three-speed manual transaxle located in the rear. It ran very well, but got nowhere near your mileage.

[cRiPpLe_rOoStEr]

Originally Posted by MeteorGray

It reminds me of a '63 Pontiac Tempest I had. It was powered by a 326CID V8, if I remember correctly, with a three-speed manual transaxle located in the rear.

The 1st generation of the Tempest was a really interesting design, even though some of its features didn't make their way into the following generation.