What kind of mpg could i get out of these setups?

[DustyNova]

366T BBC 4.10 gearing 700r4 tranny

336T BBC 4.10 gearing th400 tranny

366T 373 gearing th400 tranny

336T 373 gears 700r4 tranny

1986 k5 blazer 33 inch tires 4 inch lift 4 wheel drive

[tucsonjwt]

I will guess - 8 mpg with any of those set ups. (If you don't get on it.)

[DustyNova]

can you tune a 366 up for good performance? like to 450 horse and 5 something torque?

[DustyNova]

also what does it make with a 402 crank in a 366 block also would it be better to have a manual or a automatic

[Titomars]

I have a 454 with Q-Jet, TH400, and 3.73 posi. Around town 8 mpg is pretty normal and I drive with a semi heavy foot. On the highway I never checked what I get. I am guessing around 11 or 12 mpg @ 65MPH and spinning 3300 RPM.

[geezer#99]

Originally Posted by tucsonjwt

I will guess - 8 mpg with any of those set ups. (If you don't get on it.)

I woulda guessed a couple less than that. 5-6 mpg if you're lucky.
Only way to get 450 hp out of that chunk is with a 300 shot of goofy gas!!
As for the 402 crank. The 366 has the same one. Same stroke.

[TwoFiftyShifter]

Originally Posted by Titomars

I have a 454 with Q-Jet, TH400, and 3.73 posi. Around town 8 mpg is pretty normal and I drive with a semi heavy foot. On the highway I never checked what I get. I am guessing around 11 or 12 mpg @ 65MPH and spinning 3300 RPM.

3300 rpm would be 75mph with 3.73s with a 29" diameter rear tire.

Perhaps your speedo is off or you have 4.11 gears.

[Titomars]

speedo does not work yet. I checked with a GPS. I have 27.5 inch tires in the rear

[DustyNova]

is it worth building? am i better off building a 427?

[geezer#99]

Originally Posted by DustyNova

is it worth building? am i better off building a 427?

Only if you have a deep wallet!!
If the 427 is a short deck motor, then go for it.
If it's a tall deck like the 366 then you need even a deeper wallet.
Build a 454 or 496. Less money, more power.

[DustyNova]

Originally Posted by geezer#99

Only if you have a deep wallet!!
If the 427 is a short deck motor, then go for it.
If it's a tall deck like the 366 then you need even a deeper wallet.
Build a 454 or 496. Less money, more power.

im sure i can get a 454 block at the wrecking yard i mean couldnt i just order a 427 crank and pistons and itd be the same thing?

[geezer#99]

You can make a short deck 427 from a 454 block. Check the specs between each motor.
http://en.wikipedia.org/wiki/Chevrolet_Big-Block_engine
But don't just go order a crank and pistons without getting and checking out a block first.
If you've got the coin just stroke a 454 and make a 496.
There's no substitute for cubic inches!!

[DustyNova]

Originally Posted by geezer#99

You can make a short deck 427 from a 454 block. Check the specs between each motor.
http://en.wikipedia.org/wiki/Chevrolet_Big-Block_engine
But don't just go order a crank and pistons without getting and checking out a block first.
If you've got the coin just stroke a 454 and make a 496.
There's no substitute for cubic inches!!

is there anything above a 496 just curious

[Bigstevex4]

In 1978 I ad a 2 ton Chevy set up for giant tire service had a 366 5 speed 2 speed rear.
Gassed up up going out town before I left drove 10 miles round trip ran about an hour boom and compressor ran off pto topped it off took 21 gallons. I figured it got around 2to 3 mpg 2 45gal saddle tanks. I would say bad very bad.

[geezer#99]

Originally Posted by DustyNova

is there anything above a 496 just curious

Of course!!
Some over 1000 ci!
Just google bbc stroker combinations!
You're only limited by your wallet!!

[Bigstevex4]

Originally Posted by geezer#99

Of course!!
Some over 1000 ci!
Just google bbc stroker combinations!
You're only limited by your wallet!!

There's a 600ci small block all aluminum.

[DustyNova]

1000ci 0_0 LOL HOLY **** well i thinka ima stick with a 427

[slotard]

Originally Posted by Bigstevex4

There's a 600ci small block all aluminum.

From what I'm finding it has 4.6" bore spacing and 10" deck height, so not much of a small block.

[D13]

366/396/402/427 use the same cranks. 366 is designed for high load low to medium RPM, 4 ring pistons, peanut port small port heads. Usually has good steel crank and good rods. Take those and a 454 block and you have a stout bottom for a 427. None of these are MPG motors. 700R4 built to withstand a healthy big block costs more than the mileage over a TH350/400 gain repays for 50k miles.

[slotard]

One of the advantages of the 700R4 is that it increases comfortable cruising speed. With my 350/350/4.10 on 30" tires, cruising speed isn't that high - I tend to stick to 55 or so. With OD I could probably cruise at 65 or 70. Fuel consumption may not be any better, but it's nice to get there faster. Of course, a taller rear end would also help, but that would sacrifice speed off the line.

[cerial]

If you want mileage install a manual. I have gotten 8mpg average in a 454 longbed automatic 81 and 15mpg in a 454 longbed manual.

Same stock engine with only 9,000 miles separating the two. Both c10 trucks with stock engines. One had a TH-350 and the other had a sm465. Both had 4.11 gears. Both ran great. The difference was that I was able to coast a majority of the time with the manual running 800 rpm occasionally putting it back into gear and getting up to 70mph. while with the automatic I was running 3 times that at 70mph and could not do much about it.

Once you have a manual decided you can look at the engine.
The price to build a 496 is quite higher then just building a 454. A 468 can be built for way less time/money then a 496.

Of course if your willing to keep a open mind there are other options. If you are after cheap torque and don't mind paying for premium fuel. The late 60's-early 70's Buick, Olds, Pontiac, and Cadillac Big Block engines put out around 500 ft/lbs and can be be had with a entire car for less then $1500 if your willing to look. The difference is that these engines have a high nickle content blocks making them lighter then 454 blocks. They can be built up to outrageous power numbers or will run great in stock form as long as you keep them under 4000 rpm. Adapter plates are out there to make them a easy bolt in deal. The only downside is that the B,O,P,C engine does cost more to upgrade/rebuild then your common Chevy engine.

[greg64]

I think the B,O,P,C engines are interesting, and the 500 ft-lb is nothing to sneeze at. But trying to couple these engines to an overdrive stick would be an adventure.

It's the Buick engine that's much lighter than a BBC. It was a new thin wall casting process.