vortec heads on 350

[Paladin]

My 454 block is dated 77. It has been bored .060 and stroked to a 496 using a Slip White rotating assy. Compression is 10.6:1. Running 781 heads. It runs great with 93 octane.

Nice, my 468 runs great on 92-93 octane, comp is 10.5, gives me around 9-10 mpg whenever I can keep my foot out of it and a stiff tailwind! Regular 86-87 octane and it chokes, spits, sputters and runs like molasses!

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[Dan Brown]

For what you say you use the truck for, I'm a firm believer in "there's no substitute for cubic inches". I'd go with the big block, and build it wisely, i. e. fairly low compression ratio, low end cam, etc, etc, so you don't have to carry a chemistry set around with you to avoid knock. I wouldn't worry about mileage, as it ain't gonna be worth a flip anyway. Get lots of low end torque, and pull what ever you want, as long as the rest of the drive train can handle it.

 

[1983ChevyK30]

it is a 1 ton so i think the drive train will be fine. i wanna build it up a little just because i wanna go through it anyway because i want to replace all the gaskets and re-ring it.

 

[trukman1]

In '79 I had two friends, one with a brand new truck 350 K2, the other with and older '76 454 C20. The one with the 350 wanted the power from the BBC and the other wanted the better gas mileage from the SBC. They swapped and the difference was 1 mpg! The owner of the original 350 truck was PO!!!

To be fair, before dropping the BB into his truck, my friend with the K20 installed a 268H Comp Cams camshaft/lifters combo.

I later built a 461ci with the same camshaft and barely noticed the difference in mpg over my old SB trucks. Couldn't have been happier!

One professional mechanic told me he heard that same thing whenever people swapped in a BB. He theorized the BB didn't have work as hard to move a heavy vehicle like the SB and thought that was why.

One last example, my father went on an elk hunt out west (I'm in Ohio) and they took a 350 K20 and a 454 K20. He said they both used close to the same amount of gas but going through the Rockies the 350 lagged going up the mountains while the 454 barely seemed to notice the difference.

Just some personal experiences.

 

[Catbox]

The 454 in my truck is a hungry one.
You will soon find the lowest fuel prices around as you will be there frequently.
Mine isn't a daily driver and when ever we take it out I seem to need to stop by the gas station.

 

[Rusty Nail]

In '79 I had two friends, one with a brand new truck 350 K2, the other with and older '76 454 C20. The one with the 350 wanted the power from the BBC and the other wanted the better gas mileage from the SBC. They swapped and the difference was 1 mpg! The owner of the original 350 truck was PO!!!

To be fair, before dropping the BB into his truck, my friend with the K20 installed a 268H Comp Cams camshaft/lifters combo.

I later built a 461ci with the same camshaft and barely noticed the difference in mpg over my old SB trucks. Couldn't have been happier!

One professional mechanic told me he heard that same thing whenever people swapped in a BB. He theorized the BB didn't have work as hard to move a heavy vehicle like the SB and thought that was why.

One last example, my father went on an elk hunt out west (I'm in Ohio) and they took a 350 K20 and a 454 K20. He said they both used close to the same amount of gas but going through the Rockies the 350 lagged going up the mountains while the 454 barely seemed to notice the difference.

Just some personal experiences.

Great post!

 

[shiftpro]

The 454 in my truck is a hungry one.
You will soon find the lowest fuel prices around as you will be there frequently.
Mine isn't a daily driver and when ever we take it out I seem to need to stop by the gas station.

Get a larger tank, problem.... mitigated.

 

[shiftpro]

For what you say you use the truck for, I'm a firm believer in "there's no substitute for cubic inches". I'd go with the big block, and build it wisely, i. e. fairly low compression ratio, low end cam, etc, etc, so you don't have to carry a chemistry set around with you to avoid knock. I wouldn't worry about mileage, as it ain't gonna be worth a flip anyway. Get lots of low end torque, and pull what ever you want, as long as the rest of the drive train can handle it.

IMO low compression is guaranteed poor fuel economy, just saying..

 

[shiftpro]

In '79 I had two friends, one with a brand new truck 350 K2, the other with and older '76 454 C20. The one with the 350 wanted the power from the BBC and the other wanted the better gas mileage from the SBC. They swapped and the difference was 1 mpg! The owner of the original 350 truck was PO!!!

To be fair, before dropping the BB into his truck, my friend with the K20 installed a 268H Comp Cams camshaft/lifters combo.

I later built a 461ci with the same camshaft and barely noticed the difference in mpg over my old SB trucks. Couldn't have been happier!

One professional mechanic told me he heard that same thing whenever people swapped in a BB. He theorized the BB didn't have work as hard to move a heavy vehicle like the SB and thought that was why.

One last example, my father went on an elk hunt out west (I'm in Ohio) and they took a 350 K20 and a 454 K20. He said they both used close to the same amount of gas but going through the Rockies the 350 lagged going up the mountains while the 454 barely seemed to notice the difference.

Just some personal experiences.

I have seen this before as well, in late 70's and up. 454's in square bodies getting 15mpg was not uncommon. Mind you, none of these were stock.
At the very least they had headers and bumped up compression and rv cams.

I've mentioned here before that I worked in a rebuild shop and we seldom rebuilt anything without putting in higher compression pistons, and rarely if ever a stock cam. Customers always claimed more power and fuel economy... life was so easy back then...?
I still wonder how we got any power out of those sbs back then (with the crappy heads)... oh yeah right, we plowed larger valves in them and wore out a few
carbide cutters. (didn't have CNC porting machines back then. Like I said, life was easy)


The guys that wanted LOTs of BB power went with high rpm cams and big carbs and man did those mills ever drink! Worse than the worst running BB pulling
a 0ne ton 4x4 with high gears and big tires...

 

[4WDKC]

In '79 I had two friends, one with a brand new truck 350 K2, the other with and older '76 454 C20. The one with the 350 wanted the power from the BBC and the other wanted the better gas mileage from the SBC. They swapped and the difference was 1 mpg! The owner of the original 350 truck was PO!!!

To be fair, before dropping the BB into his truck, my friend with the K20 installed a 268H Comp Cams camshaft/lifters combo.

I later built a 461ci with the same camshaft and barely noticed the difference in mpg over my old SB trucks. Couldn't have been happier!

One professional mechanic told me he heard that same thing whenever people swapped in a BB. He theorized the BB didn't have work as hard to move a heavy vehicle like the SB and thought that was why.

One last example, my father went on an elk hunt out west (I'm in Ohio) and they took a 350 K20 and a 454 K20. He said they both used close to the same amount of gas but going through the Rockies the 350 lagged going up the mountains while the 454 barely seemed to notice the difference.

Just some personal experiences.

This is the reason I was thinking 454 for my truck as the 350tbi was only getting 10-12mpg