Inliners International Forums General Discussion Engines Engine Choice Dilemma...

Hey guys, I've been lurking around and haven't posted much, due to having a bent 8 in my truck, a '69 GMC, with a 3 on the tree, and 3.07s out back.

However, I'm in the process of deciding if I want to change that. And this is where my dilemma starts.

If I were to keep the 307, a rebuild is in order, so I would anticipate rings and bearings, gaskets, just a quick freshening up on it. I already have headers, and with the stock intake i'm pulling around 15 mpg as a daily driver.

However, I've always been a sucker for a six, and should I go the 292 route, it would get a general freshening, rings, gaskets, bearings, probably a quick valve job and seals. It would also become the proud wearer of a 3x1 Offy and Headers, since I've been sitting on them for some time now, waiting for a 6 build. A small cam may also be in order, pending funds at the time.

My issue comes with trying to figure out which would be the most effective. I drive my truck everyday, and it gets used as a truck on the weekend. I've heard mixed reveiws from other boards, and I wanted to get an inliners perspective on it.

That being said, I'm also trying to keep this fairly cheap, because I'm in college..and..well. Thats really all I need to say on that note. haha.

So, if anyone has any input, I would greatly appreciate it, especially pertaining to past experiences, and what you think about a mpg vs. hp vs. torque comparison between the two engines.

thanks in advance all!

-Sam.

Sam, Pretty new to this stuff myself. I've got a 69 olds F85 that I've had since college (86!), came special order from the factory with a 250 in it. I did the usual easy Clifford stuff to it--Clifford intake, headers, small 4 barrel carb. Stock I remember it knocking down close to 20 mpg, its getting a lot less than that now with the after market, but I don't have it tuned correctly. (Like I said, still learning)

Santucci's Chevrolet Inline Six-cylinder power manual is a wealth of knowledge; a great source of info if you decide to start modifying a 292.
Dave

v8 is a lot cheaper, if thats the main goal take the v8, but if you want to take the high road and want something just a hair bit different with some flavor and pizzaz, then hit the 292, its a good motor and will run well with a load and do well just as a a daily driver ya know, 3.08's are kinda low but with just the 1:1 rear ration of a 3 speed final gear, it should be ok-ish? little low for me though, byt should retain adequetly good RPM's on the freeway and not suck too much gas, the gas mileage will probably be about the same, or maybe a little more, but not alot. I think that the big advantage for the six would be good low end torque which will be good USEABLE power while driving around, because how many of us really ever see 5000-6000 RPMS anyway, so for its purpose of off idle and mid-range power the 292 will be great!!! This motor doesn't tend to get too expensive until you get into the guts of the motor, like head work, pistons, hi-performance parts and so on, but maybe with a couple of langdons weber carbs (cheap by the way!!!) and HEI, and a set of headers, mild cam and maybe a quick block/deck shave to get that compression up to adequete levels, like 8.5-9.0 range, you would really like this motor and retain good mileage. but a v8 will most likely in all cases be cheaper, especially when coming to the guts and performance parts/head work, but it also depends on how much work each motor needs once the rebuild comes ya know!!! good luck and GOD speed, keep us posted

I agree, you already have the 307 and they are about the cheapest engine to buy parts for and rebuild.

As far as power and mileage goes there isn't much to choose between a 307 and a 292.

You might eek out a little more mileage with an RV cam and fuel injection. Throttle body injection off a 305 for example.

Thanks for all the replies all.

Since this truck is my work horse, daily driver, hot rod..all compiled in one, i like to be a bit different. plus, i've always been a sucker for a sixer, thanks to my dad's wisdom shining through at an early age, and realizing that low end grunt is your best friend when hauling. That, and he has always wanted to build a hot six, or atleast luke warm, haha, and this would give us a chance to do that.

With the 30.7's, it lugs some off the line, but at 55-60 mph it's turning a nice 2000 rpm's. Which helps with fuel immensely.

There's a machine shop just over yonder, that does alot of racing work for my friends and relatives, i think i can get the block and head decked for about 200 bucks, which would help the compression, and make sure everything is trued up. Thats assuming the engine doesn't need to be bored.

and, since i'm already sitting on a 3x1 intake, headers, and the 292 has an HEI stabbed into it already...it's getting harder and harder to NOT want to build the six cylinder.

I guess i won't know the specifics unti i get one of them torn apart. Which will be the 292 first, because i can build that, while still driving the truck.

Thanks again your take on this guys, it measn alot to me. and feel free to poist some more opinions and/or experiences!

-Sam.