454 Vs 383

[folkenheath]

I used to get 10 MPG with my SBC, I now get 11 MPG with my BBC, w/ a 10" converter that slips 400 RPM going down the highway. Its got higher compression, which makes it more efficient, along with EZ EFI vs low compression and the carb on the SBC, but I didn't have the slipping converter on the SBC either. That converter is great on the sand, but sucks on the freeway.

But I should say, when I beat it on in the dunes I actually get 2 -3 MPG. And its probably worse than that, because that's based on the odometer, and how many miles did I drive in the sand vs how many miles my tires traveled in the sand?

But who's worried about fuel mileage on the toy? It's not the daily...

 

[DRYANKNPULL]

That’s a great point about your mission, and we all have different missions. I do pretty mild trails on my properties, but I needed ground clearance. I have a four inch lift and 35’s to get my axles and bumpers off the ground. Now I need to pull a 18 foot trailer with a couple of wheelers on it and go up a hill faster than 50 mph. I know I need to have the diffs regeared and plan on getting it done while the engine is done. I don’t know a whole lot about engines (and frankly most of what I know I’ve learned here). I do know that I like displacement, torque, and horsepower.

 

[ZooMad75]

I’m getting the same mileage with the 8.1 as the 5.3 in normal driving. I call that a win. The 8.1 isn’t working nearly as hard as the 5.3 was and don’t spin anywhere close to the rpm the 5.3 did to maintain speed on hills or into headwinds.

 

[JDJ2810]

I daily my 84 K5 at the current time. The 350sbc has a small cam, intake, and Holley truck avenger carb. the 700r4 helps on the interstate. Currently 3.73 gears. I decided to buy some cheap aluminum heads for the 350. I have a Dana 60 front axle with 4.10 gears on the way. I will put FF 14 bolt in the back. Once again the 700r4 will help on the interstate.

I wouldn't hesitate to toss in our aluminum head 454, but we are gonna put it in Dads 71 Nova. I have another 454 I can put together If I decided to go that route. Its just hard to be the massive TQ and BBC can make.

My concern in the BBC and the 700r4. Dad has a 72 C10 with a happy 402 BBC and a built 700r4 that seems to be fine. I just don't have much experience with that transmission.

 

[6872xtc]

I daily my 84 K5 at the current time. The 350sbc has a small cam, intake, and Holley truck avenger carb. the 700r4 helps on the interstate. Currently 3.73 gears. I decided to buy some cheap aluminum heads for the 350. I have a Dana 60 front axle with 4.10 gears on the way. I will put FF 14 bolt in the back. Once again the 700r4 will help on the interstate.

I wouldn't hesitate to toss in our aluminum head 454, but we are gonna put it in Dads 71 Nova. I have another 454 I can put together If I decided to go that route. Its just hard to be the massive TQ and BBC can make.

My concern in the BBC and the 700r4. Dad has a 72 C10 with a happy 402 BBC and a built 700r4 that seems to be fine. I just don't have much experience with that transmission.

My experience is that if you build the transmission to take as much as possible, it should last a long time, as long as you know what would be most hazardous to it. Don't tow heavy in OD, don't run around at low speeds in OD without the convertor locked.
Mine has a billet input drum, Corvette 2nd servo, Transgo shift kit, larger boost valve. The next step up from where it is, was going full manual. It has 48K on it behind the BBC.