E85 500 HP 383 with a L31 truck intake

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Bloke

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So you're going to run a 7 cylinder truck?

I'm thinking adding that 8th cylinder would be worth all the other proposed upgrades combined..........










Cheaper too.
Naw i just pay some 30 bucks for the last one. Its a knuckle scraper. I will save money when I can but at my age, time and income I just pay someone to do this.
 

L31MaxExpress

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Buttoned it back together yesterday afternoon and into the early hours this morning. Put the marine MPFI dual plane on it with an Edelbrock 600 and a HEI. Put a spare starter on it and connected it to a battery and used a 5 gallon gas can to fuel it. Sounds healthy with open long tubes. When I hot lash the valves tomorrow morning weather permiting will try to get a video clip. Cold lashed it sounds good. With a 600cfm carb this thing is super responsive with only 4° initial advance and 26 total timing.

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L31MaxExpress

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Here is what it sounds like. Did not bother dialing in the carb or distributor. It will run even smoother with the heavy 4L80E torque converter and all the accessories on it with a full exhaust and EFI. Not sure why but the microphone on my phone picks up the rhoads lifters about 2x as loud as they are in person.

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L31MaxExpress

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I am going to have to do a little digging into the engine. Did a cranking compression test. 210 psi in every cylinder except #2 and that one is 185 psi. Loosened the rocker arms a half turn on that cylinder and it stayed the same. Leak down test in a day or two when I get time to figure out why. If its not leak down, will swap the rhoads lifter on the intake lobe from another cylinder into cylinder 2. Might have a lifter that is not collapsing like it should. If it is a sticking lifter, will disassemble it and find out if it got a little debris or something stuck in it. The other 7 cylinders snap to 150 psi on the first puff. The low cylinder goes to 120. A couple of squirts of oil did nothing. This is the exact reason why I ran it on the stand rather than putting it in first though.
 

L31MaxExpress

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Got it figured out. Rocker arm was too tight. Hooked up the vacuum advance and ran it for a while this evening. Idles at 750 rpm with nearly 20 in/hg vacuum. Free revs 2,500 rpm with 24 in/hg vacuum. Moved the accelerator pump position on the Edelbrock 600 to give it more of a pump shot. Lightning fast throttle response now and free revs like crazy on the primaries. Going to be a strong runner with excellent manners.
 

Supercharged111

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Really? I would have figured with the 29" tires and 2wd you'd fare better than that.
 

L31MaxExpress

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Really? I would have figured with the 29" tires and 2wd you'd fare better than that.
With a 5.13 gear and LT285/70R16s kinda doubt it. The 2wd 8.1/4L85E/10.5" Avalanche/Suburban loses right at 25%.

2wd 4L60E and a 7.5/8.5 loses about 18-22% depending on if it has a mechanical fan or electrics.
 
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