The Stovebolt Site Forums The Shop Area The HiPo Shop mileage advise?

hi all
cant decide what motor to run in my 49 3100

it needs to pull well go well cruise at 70 all day
be happy in traffic AND give good mileage
can anybody tell me what sbc set ups could do this? (nothing exotic)
manual or auto and a good cam for torque/mileage
what sort of mileage are u guys getting?

also whats best axle ratio?
thanks

I have a '49 3100, '56 235 6 cylinder, '848 head', Fentons, dual 30" glasspacks, '62 3sp+od, '57 3.90 diff., 1-2bbl H-W, 215 85R 16 Michelins (no tubes needed). I drive 70-75 all day (two 900 mile trips so far this year)20 mpg highway.

he says good mileage !!!!!!!

250 or 292 L6 motor
T5 or NV4500 5 speed
10 or 12 bolt rear
set the motor up any way you can afford to.

gl

Blown 454 with a built 700R4.

well i think i got a wheezer 216 so was thinking of a 283 or 305 /350 v8 just wondering what mileage to expect
and whats a good cam choice

I've got the Edelbrock cam, 2101 intake and 600cfm carb setup on my 283... but my mileage sucks, because the carb is messed up..

I have a 350 SB and a built 700R4 in my 55 2nd.3:90 rear.20 MPG will cruise at any speed you desire.

The 700R4 transmission gave me a little increase and the TBI system that replaced my Q-jet gave me another increase but I'm still only getting 14-15 on the highway with my 350 ('65 C20).

persh,what gear ratio is your rear?

Hey, I didn't want to answer your quesiton too quickly!! (Sorry, I haven't been around here much lately). I installed a Dana 60 with a 3.54 gear set.

what do you consider good mileage? I do know small block chevy and good mileage should never go in the same sentence.

Why shouldn't a small block get good mileage? Set up right they should be very good on fuel mileage.

You are going to get 100 different answers to the fuel milage question. I would bet no more then about 20 at the best and most likely about 15 to 17. The truck is pushing a ton of air so no matter what engine you give it, its going to have to work harder then a modern truck would. My 250 with automatic and 3.08 gear gets 18 at 70 mph in a 3300 lb truck.

Joe

I am of the opinion that if you are driving one of these you aren't really concerned with fuel economy, I don't feel less than 30 mpg should be regarded as good mileage. If this is just a toy thats one thing, but if you are going to use it as a daily driver, I consider 20 mpg nearly criminal. (yes I put suburbans, expeditions and the rest of them in that category) But that is just me, the sheer number of them on the road makes its own statement. I am pretty upset I only get 34 mpg in my little bitty car, the truck I don't even want to know...but then I only drive it occasionally. To each his own, that is just my feelings.

You say you want to be able to haul a load and cruise confortably at highway speeds so some type of overdrive is a must. The 3.90 rear mentioned is a good choice as this gives a 2.73 final in od which is about as shallow a gear as can be pulled comfortably with a load and a stock 350. Radial tires at recommended pressure, synthetic oils and fluids, free flowing exhaust, coolant temp as high as possible without losing any, FUEL INJECTION, no sun visor/west coast mirrors/bug shields or other air catchers and your driving style will all be factors. Why the hang up on 350's when the newer LS engines are so much better and give great mileage right out of the box. It's the reason GM canned the old sbc design. Price and electronics would be my guess but the results are undeniable.

Reminder: This forum is about old Chevy trucks. If you want to discuss the mileage you get in your modern vehicles, please do it in the Greasy Spoon. Please limit this to a discussion on how to improve mileage in our old trucks.

Thanks.

ok fine! I recommend the 350 w/tbi and either standard transmission already mentioned.

The original question is all about a modern drive train or modifications.

OK, I'll move it to HiPo then.

So how about undeleting my original post? Bet ya can't do that.

my advice is a good strong 350 with a rv cam and maybe a expertly built q-jet and a recurve hei. run the 700 r4 with maybe a 3.70 or 3.55 gear. whenpulling the load run in drive not overdrive. it will kill the mileage but save the tranny. and as always let it breath well. long tube headers with free flowing exhaust and a good fresh air intake system. i would bet once tuned right it will run in the 20's. i ran this setup with out the headers and fresh air system in my 82 chevy and got 18-19 consistently. so with the extras i would add a few more mpg.

I've got a 48 3100 running a 283, quadrajet, headers, TR700 and 3:90 gears. It'll run 70 all day long but that big ole visor on the front acts just like a big ole wind brake, so I'm only getting 11/12 at best on the highway. Remember they didn't build those things with aerodynamics in mind, it was a work truck. I'm pretty sure the highway speed limit in 1949 was 50 mph. I would agree that if you think you can have all that you'll have to be thinking LS ....