Opinions needed???

[truckdrivinsob]

Hey guys been a while. Been driving the pick up everyday and just aren't happy with the v8. Mainly because i cant keep my foot out of it and mpg's are not that great. I have a 292 out of a 66 Chevy c20 government truck. It needs a little freshening up but no big. I just want a nice cruiser basically and since my son is gonna get it, it doesn't need to be a race car.

My mind is made up just want to know what you 292 guys think? It will have the th400 from the v8 and 3.05 gears in the rear end. Any thoughts?? Will it run ok with that drive train?

Thanks in advance!!
SOB

[Shaky]

292/TH400/3.07 will cruise nice. Just be warned - 292s do not get good mileage. What they do is give lots of torque down low.

[truckdrivinsob]

At least little better than 12ish ???

[cayoterun]

We used alot of 292s on small irrigation wells. They'll run forever and ya' can't break 'em.
Don't know anything about mileage as they run on natural gas. Just know they're are tough and lots of torque. For a smaller motor, I don't think there's a better engine.

Cayoterun

[Shaky]

Originally Posted by truckdrivinsob

At least little better than 12ish ???

Unless your V8 is crazy, it'll be about comparable. I'm keeping the 292 in my '67 because it's original and I have a lot of parts for it.

The 250 is a different animal and you can squeak some decent mileage out of them.

[markeb01]

Depending on what V8 you have, and if it's in decent condition, you should be able to do a lot better than 12ish with some modest upgrades. Perhaps a new carb, HEI, tuning on the carb, new plugs, good wires, etc. Of course the end result also depends on the rear axle ratio and as you noted - driver restraint!

Years ago I got better mileage after a 283 swap than I did with the original 235, because I didn't need to push it so hard to perform. With the 6 I drove with my foot on the floor all the time to get similar performance.

[truckdrivinsob]

OK well i am just over the v8 and i got the 292 siting there. i understand the work harder principle so.i guess its a give it a try and see what happens.

[Frizzle Fry]

The flow through heads of a small block offer better volumetric efficiency versus the single sided I6 head. Build a flow though head for your 292 and you might improve mileage over the V8. But the cost to do that would defeat the econimics of the swap.

[truckdrivinsob]

Well damn!! Maybe new carb and manifold swap? I have an old offenhauser(?) dual plane on it and an 585cfm holley. It has pertronix in the dizzy and a high volt coil. They are the big valve heads so idk???????

[K-TEN]

The Turbo 400 will eat up quite a bit of power to just get it moving. A Turbo 350 or a standard would help in the mileage department. And if your going to swap transmissions, then just get an early 700r or 200r. You could probably trade even with someone looking for the 400. The overdrive of a 200r will definitely help in the mileage department, as well as the reduced power necessary to get that trans moving.
A 292 has 7 main bearings and is a tough motor. There is a ton of performance work that has been done by Leo Santucci. Look for his books. With some careful parts selection and some fine tuning, you should do quite well with that 292.

Amazon.com: Chevrolet Inline Six-Cylinder Power...

[truckdrivinsob]

Really the th400 would effect that? Hum i think i am leaning towards carb and manifold swap. I just dont know any more????????

[BR3W CITY]

the th400 is a tough tranny but will drag the mileage down. i second the 700r4 if you have to do it. the od will be nice for cruising and mpg. I would tune the v8 up, and run an overdrive trans. better mpg and you don't have to sacrifice having the 8

[truckdrivinsob]

Ok sounds like the way to go. The motor has just been gone through so i am not worried about that. Just got off the phone with a friend and he says it sounds like electronics going bad maybe pertronix is messin up? I am on the look out for a 200r4 but i was told the gears would need to be changed so maybe just do a th350??

[burbguy]

I'm not a gear guy, but running the 700r with a set of 3:07's out back sounds like it's going to be gear'd too fast. the t350 idea might be the ticket, as you don't need an overdrive with those gears (depending upon your tire size)...? just my 2 cents...

[truckdrivinsob]

ok sounds good, tires are 225/75r15. I think the electronics are going hay wire with further research in to my problems. i dont want to go hei i dont like the looks of them but may haft to! i have heard the same thing on the 700r4 if i would have left the 4.11's it would have been perfect.

[Rogue]

No way I do a build these days without a OD.

[EVBuilder]

For those that don't like the look of HEI here is an alternative. Also I agree the TH400 is a power hog. I have heard they eat more power than any other automatic. TH 350 is way better for that.
http://www.summitracing.com/parts/MSD-8474/ [/URL]

[truckdrivinsob]

Originally Posted by EVBuilder

For those that don't like the look of HEI here is an alternative. Also I agree the TH400 is a power hog. I have heard they eat more power than any other automatic. TH 350 is way better for that.
http://www.summitracing.com/parts/MSD-8474/ [/URL]

Ouch!!! I can get a new HEI at super shops for 69 so i might just bite the bullet and do it. Hey i guess i dont haft to open my hood!!

[astrochimp]

For MPG you need to pick part to make power in the RPM range you drive in. Most aftermarket parts make more power at higher RPM but lose power where most of us drive..

An early 70's cast intake and q-jet are very hard to beat.


Finally did a base MPG on mine the last two weekends, right at 10. Actually it was even worse when I got the truck.

[Frizzle Fry]

A good dual plane aluminum manifold will be hard to beat for mileage/performance in a street-driven truck. Edelbrock Performer or equivalent would be my choice for your application.

[Russ65C10]

I stear away from a 200R4 behind a 292, too much torque. With the 3.08 gearing I'd go with TH350 or 700R4 although with the 700R4 I'd seriously think about about going with a lower geared rear end.

[truckdrivinsob]

Russ i would not not be switching motors if i go 200 or 700 r4. I am just trying to make a choice between v8 and od or 292 th350

[Russ65C10]

Ok, I went back and read your original post ;-)

Go with the 700R4, you get better mpg than with the 292 they're gas hogs. But don't expect to way better mileage. Here my experience. Keep in mind I have always like to "put my foot in it".

66 Short Stepside 250 inline 6, 3 speed, 3.73 rear end. 12 -14 mpg

65 Short Stepside 283 V8, 3.73 rear end 1st with a powerglide later with TH350 10 -12 mpg

65 upgraded to 700R4 12 - 13 mpg not much of an improvement.

What will get with OD is a truck that will cruse down the freeway at something like 2000 rpms, which makes for a much nicer (quiter) ride.

[Russ65C10]

BTW - unless you're willing to spend a chuck of change and know a good tranny builder that knows their stuff on the 200R4 I wouldn't put it behind anything other than 250 or smaller inline 6. I tried the 200R4 route (it was a direct bolt in replacement for my powerglide) before I went with 700R4, the 200R4 in stock form is just not up to snuff behind a non-smogged small block. My basicly stock (headers & edelbrock performer intake/carb) 283 took no time at all to eat a 200R4.

[truckdrivinsob]

Thanks for the info russ! I have heard the same thing about 200s i got a buddy giving me a 700 so i will go that route.