The Stovebolt Site Forums The Shop Area Engine Shop NEW Project!! Engine options: Small blocks vs. BIG blocks

Got a new project and looking to get a little creative with it, and want to discuss engine options. I'm torn between Small blocks and BIG blocks. Speed is really not an issue, since I just want a reliable cruiser with decent mpg. Some people say big blocks get more mpg bcs they have to work less, other say small blocks are lighter and have plenty of power but if I'm going to get similar/close mpg then I rather have BIG block power. What do you guys think...what are some good engine, trans and gear ratios for mileage?

This discussion belongs in HiPo.

dosen't anyone on here have a recipe for a good cruiser?

Heavychevy, not yet anyway.....my friend is putting a 454 in a 53 2dr sedan. It WILL make a nice cruiser.
I've always hear "you can't beat the cubes" so go big! Its more of a personal thing of what you want, or what you have on hand around the shop. Do you want to SOUND fast or really GO fast...and I mean FAST.
As an example I have a 283 on my engine stand an I THINK I want to build a 301 out of it like I had back in the mid 60's. It want be no slouch but it won't be the fastest thing on the street either but hey, I'll like it.
What kind of body car/truck do you have or have in mind. If its a 39 there may be some drawbacks with the big block, meaning a pain in the butt if your not careful. Me, I love to hear the small blocks winding up. Nothing like it.
And lastly.... most of us here are not short on "opinions" but most all of us will say its YOUR vehicle so do what YOU want as long as your not destroying a good original. LOL

Come on guys, give heavy40chevy your OPINIONS!

I got a one year "69" 396 big block 2 barrel intake and carb. If you want to run a big block and save some gas.

I have a bunch of 39/40 parts and stuff left over from my 40 truck restoration so i'm looking to put them to use, in some shape or form. lol Never really messed around with V8's (mostly 216's splash dippers) so I've been itching for one, but I'm not sure what kind. From what I've researched it seems like guys are getting anywhere from 10-20 mpg with both SBC/BBC pending the set up ect. What I'd like to do is figure out a direction to go for a cruiser that gets around 17-23 highway I've tossed around ideas of 383's 400's or even 454's with overdrives, small cams, tuned carbs etc. (big torque) although at the same time I've heard 283/ 307's doing pretty well too. (along with MPG horror stories with every engine, I've listed). I'm not building a V8 for gas mileage but I plan on driving these alot of miles (highway and country roads), so it is a valid concern.

I don't have my mind set on a specific build so I'm open to hearing any type of experiences/ builds you've done to make a fun 17-23 mpg driver. Anything from a 283 to a 454 is fair game

If you are looking for 17+ mpg forget the big block, just not going to happen. If you want that kind of mileage you should maybe look at a modern LS motor with all the modern technology stuff, then you will maybe get your 17-23 mpg.

Even with a small cam, overdrive and a gear ratio 2.70 on all highway..or is that still just unrealistic?

I guess the modern engine would be the easiest route to go but also costly, I've also heard alot of the Buick guys claiming to get 20 mpg with 455's with those boats and even some hopped up 454 big blocks ones hooked up to "gear venders". Some of those posts are old so i havent been able to substantiate any of those claims

Ok, I'll chine in. I've got the belly button in my GMC with a 3 spd. With the gearing in my rear, 3.07, I'm getting 16 to 17 mpg on the road. My 350 has a mild cam and a 570 cfm holly on top with 76cc heads and running regular gas. Simple and to me sounds great. The best thing about the 350 is parts are out there without having to hunt to hard.Larry

Thanks Larry, this is exactly the type of info I'm looking for.

That's what i'm liking about the 350's so far, it almost seem like its cheaper to buy a new 350 than to rebuild an engine yourself almost

also, would it be possible to squeeze more miles out of that set up with an RV cam & overdrive or would that lug the engine too much?

Let me add some more to my comments....

gearing gearing gearing.... running a hot/fast 350 in my 37 and getting around 16-17 if I'm easy on the gas pedal running a 600 edelbrock with a 2.73 gear.(79 Malibu)

running a 305 reman engine with 600 edlebrock carb and getting 17-18 with my PANEL but running a 3..38 gear.

****Both have the 700R4 tranny with overdrive. 1900 RPM's will get you on down the road at the speed limit or better!

I've heard this one, too, and there is some truth behind it. Where it becomes a factor is how much load you're hauling. Under a load, the big blocks will get better mileage than a small block with the same load. That's what the big blocks were designed for. With no load, the small block, or even a 6, will get far better mileage than a big block.

I'm only running about a 454 lift cam in my truck. It seems to pull pretty good at low speed s. I pulled my small camper, weights about 1500 lbs, to and from the reunion easily. I feel like the truck pulls well at low speeds without a lot of down shifting. I'm also running a striaght 3 spd out of a 71 c10 I blieve with 1 to 1 high gear. I didn't want to use anything with a lot of lift because I'm using stock 76 cc heads which with the flat top pistons should be giving me about 9 to 1 compression for using regular gas. Larry