Very soon she is going to be pulling herself around on a fully rebuilt 1-ton G3500 8-lug suspension and 10.5" FF 14-bolt with 4.10 gears, PYO 16" alloy wheels from a 2001-2008 GM HD truck wearing Cooper Discoverer AT3 LT265/70R16 load range E tires. 4.10s and a 30.63" tall tire should work out really well. Will put me right at 2,500 RPM @ 75 and a downshift to 3rd pulling a trailer uphill will put the Ramjet cam right into its sweet spot at 3,400 rpm.
You're having trouble with the L31 ignition? Maybe you've already mentioned it... Biggest problem we see is moisture in cap. Insert a hose nipple in one vent in distributor and connect to ported vacuum and problems go away. On LS powered vehicles the coils tend to fail around 150k miles. Then its chase, chase, chase after that unless you replace the set. For low cost maintenance the distributor is nice.
Ramjet / HT383 cam that I installed in the bus is working well. We're seeing much improved fuel economy. Should have switched years ago. Might install more cams this winter if we have the time. Had to spend some time with idle corrections to prevent surging but otherwise minimal changes were done. 302 in Suburban also had surging issue... again, changing spark values for idle speed correction solved problem. Suburban is providing 20+ mpg on highway when not towing. Better than our 4.3 powered '95 Blazer ever was.
I'm sure that full floating axle will be fun. Big brakes will be nice, too. One of these days I should take measurements to see if the '09+ rear disc hardware is a bolt on for the older vans.
Edit: I see the CC test replaced stock pcm with an 0411. I'm not sure I'd attribute all the gains to the ignition as they did.
I vented the distributor years ago to a vacuum port I added in the throttle body just above the throttle blade. I hooked a vent hose into the TB bonnet similar to the way an opti spark is vented in later years.Originally Posted by 1project2many
I think the FF 10.5 will be great too although my guess is that it weighs 450-500 lbs with the drums on it. The 13 x 3.5" drums should be a nice upgrade. I already put tue 8600 GVW front calipers and pads on it when I put the Hydroboost and 1-ton master on it.
I totally eliminated idle spark correction with my 215-220 @ .050 cam and the idle has been rock solid. I had played with the values but the old cam really liked it just being diabled with all timing maps having the same values.
My brothers 1999 5.7 with the LT1 cam and tuned black box was also very good on fuel, especially after a set of Hooker 1 5/8" long tubes and Hooker 2.25" dual exhaust went onto it. He saw 20-22 mpg on a few roadtrips. With the 40 gallon tank in the truck on a trip we went on we went through like 3 states before we had to get gas.
Good the see the 395 Marine cam is working well for you. I never have been a fan of the factory L31 cam. I never felt it had enough duration split to work well with the factory heads.
Finally I am guess you have a ton of cracked manifolds on these buses. Have you tried the Doug Thorley Bus headers on one yet? I don't know how long you plan to keep them in service but they are $615 and they come ceramic coated and well built with 14 gauge tubes and 3/8" flanges with headpipes to bolt up to the stock 3" pipes. I now often find myself pulling uphills unloaded in Overdrive that caused me to downshift to 3rd before. With 7,500# behind it I pull in 3rd gear with my 29" tall tires and 3.73s. The torques gain and MPG increase was very noticeable after adjusting the VE and MAF tables. The heads run cooler too, allowing me to dial in a few degrees more timing across the board.
The last trailer I towed for ~250 miles was about 6,500# with an older Jeep Cherokee on it. Running 65 mph @ 2,600 rpm in 3rd gear I was able to get 14 mpg. I don't recall finding a single uphill run that caused it to downshift.I LOVE the torque.
Last edited by Fast355; 08-09-2015 at 05:04 PM.
You know, as I read this I'm almost remembering you doing this. It sucks to get old.I vented the distributor years ago
Yes. You will notice the additional mass. But no more worries about bearings chewing through axles or spiders letting go.my guess is that it weighs 450-500 lbs with the drums on it.
Nice. That would probably be 5 states if you were here in the northeast!With the 40 gallon tank in the truck on a trip we went on we went through like 3 states before we had to get gas.
We've only seen a couple of cracked manifolds. I know it's a problem for people but I believe the combination of in-town driving, relatively low average speed, and less than full load trips keeps the heat down. I've considered headers (those sure are purdy!) but the cost including shop time to install was fairly high compared to used manifolds and I really have to watch spending for projects like that. Most of our 5.7 buses are approaching end of life. If I get three more years out of the '99 and '00 models I'll be lucky. It's a shame to let them go because we're literally throwing them away. Local scrap yard gave me $300 for a complete one last week. Dually rear, 4L80EHD, running 5.7, 0411 ecm. Two weeks ago we sent one down with no engine, trans, or other parts and they gave me $200. If only I had a place to store component parts!!
Rust is a pain!! The plastic trim and rubber components go the fastest here. Mine is mostly rust/rot free.
New parts are here, Old parts cleaned up and they are assembled and ready for mockup.
Last edited by Fast355; 08-19-2015 at 02:45 PM.
I also picked up a donor with a rust free and straight chassis. My Express was hit in the passenger front wheel and repaired at a young age. The frame was tweaked and stretched but it has never been right. I noticed a while back I could fit my thumb between the right front body bushing and the body!!! 303K on it runs and drives. 5.7/4L80E/3.73 GM 10.5 FF 14-bolt for $1000 with clean Texas title. The 5.7 is claimed to have about 100k on it, the 4L80E was allegidly rebuilt about 40K ago and shifts solid. I plan to hold onto it as a spare but sell the engine and all accessories and scrap the body. I plan to send the chassis to the powder coater and have it blasted and coated. I am really suprised how well it runs. It still has a completely bone stock exhaust system on it even. Nice mandrel bent dual 3" pipe to the muffler setup with the massive 1-ton cats and the weird resonator on the passenger side bank mounted before the cat.
The body and interior is trashed but I am honestly only after the chassis which is in great shape. I also noticed 1-ton vans have a factory body lift in the body mount/bushings.
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