L31 Extreme Budget Build

L31MaxExpress · Jul 10, 2024

I have a rough idea of what the 454 air cleaner and duct added power wise. Installed it and tested it earlier. It definitely pulls better above 3,500 rpm. It is noticeable seat of the pants. Years ago this same setup on my 83 with a TBI 350 increased its power from 194 whp to 204 whp with about 7 ft/lbs more torque. It went from like 299 to 306 tq negating the load in-spike of over 320 ft/lbs. Just goes to show how restrictive the stock small block TBI stuff is once you start making decent power.

Up from 57% duty cycle to 62% duty cycle to hold the same air/fuel ratio at WOT. With the 29# injectors and a 0.40 BSFC that is over 20 hp based on the math. Key on Baro reading was -0.6 in/hg. The system uses sea level as the 0.0 in/hg reading, thus at nearly 1,000 ft elevation it reads -0.6 in/hg vacuum. Its weird. At 5,500 rpm I went from -2.4 in/hg which is 1.8 in/hg vacuum to -1.5 in/hg which is 0.9 in/hg vacuum at WOT. That is 0.9 in/hg more manifold pressure and that is with a paper filter. Intake restriction was cut in half.

Big block stuff installed on a small block. There is still enough room that I could squeeze the 5.5" tall filter and taller lid as well. It would be tight, but it would fit.

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Supercharged111 · Jul 10, 2024

Nearly 1000 ft elevation! :gr_grin:

That'll be me in a month. Every one of my vehicles getting the sea level mod will be nice.

L31MaxExpress · Jul 10, 2024

Supercharged111 said:
Nearly 1000 ft elevation!

That'll be me in a month. Every one of my vehicles getting the sea level mod will be nice.

Its very nice! Then comparing the WOT vacuum. If 1,000 ft is 0.6. 2.4 is the equivalent of 4,000 ft. Stupid small block air cleaner and ducting was delivering the same air pressure to the manifold as the engine being at 4,000 ft elevation and that is before considering the density altitude was like 3,400 ft here today from the heat and humidity effects.

Orpedcrow · Jul 10, 2024

This is the coolest van. :van:

I really appreciate all the technical detail you give us in your threads.

L31MaxExpress · Jul 10, 2024

Orpedcrow said:
This is the coolest van.
I really appreciate all the technical detail you give us in your threads.

Thank You. I am enjoying driving it and enjoying building it. For whatever reason it turns heads when people hear the V8 rumble coming their way. They can have their back to me and make a 180 head turn to figure out what it is. I have heard it pull away when it was being aligned at a shop a while back and it does sound good pulling away under throttle.

It was 101F here today and it was doing what it was supposed to when I went out testing earlier. AC blowing ice cold and the engine was pegged on 195F. I actually saw the center vent temps drop below 30F before the compressor cycled driving around. Could not be happier with how the a/c rebuild turned out either.

It is not the greatest on fuel at modern highway speeds with the 3 spd non lockup TH400 but I can put a lot of fuel in the tank for what it would cost to replace it with a 4L80E without much return for the $$$ and it is much more relaxing to cruise the slower 2 lane rural highways anyway than the busy interstates.

Mechanically I am adding a trans cooler, doing the U-joints and carrier bearing and the P59 swap and it is done. Then on to finishing the interior build over the next few months. I have front seats to re-foam and re-upholster and interior to finish out.

Moofus02 · Jul 13, 2024

L31MaxExpress said:
Thank You. I am enjoying driving it and enjoying building it. For whatever reason it turns heads when people hear the V8 rumble coming their way. They can have their back to me and make a 180 head turn to figure out what it is. I have heard it pull away when it was being aligned at a shop a while back and it does sound good pulling away under throttle.

It was 101F here today and it was doing what it was supposed to when I went out testing earlier. AC blowing ice cold and the engine was pegged on 195F. I actually saw the center vent temps drop below 30F before the compressor cycled driving around. Could not be happier with how the a/c rebuild turned out either.

It is not the greatest on fuel at modern highway speeds with the 3 spd non lockup TH400 but I can put a lot of fuel in the tank for what it would cost to replace it with a 4L80E without much return for the $$$ and it is much more relaxing to cruise the slower 2 lane rural highways anyway than the busy interstates.

Mechanically I am adding a trans cooler, doing the U-joints and carrier bearing and the P59 swap and it is done. Then on to finishing the interior build over the next few months. I have front seats to re-foam and re-upholster and interior to finish out.

If you need one of those tall square body air cleaner lids let me know I'm sure I have a few

L31 Extreme Budget Build

L31MaxExpress

I'm Awesome

Supercharged111

Truly Awesome

L31MaxExpress

I'm Awesome

Orpedcrow

I don’t know what I’m doing

L31MaxExpress

I'm Awesome

Moofus02

I'm Awesome

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