L31MaxExpress
I'm Awesome
Agreed on the HP/displacement on DOHC vs pushrod. Great for a light vehicle. Too bad those DOHC engines in those trucks get almost the same mileage a 3/4 ton with a pushrod, but with half the payload capacity.
I think the DOHC engine you speak of was actually the one used in limited numbers in the Corvette in the early 1990s (LT-5?). I've read it was this engine along with Cadillac Northstar DOHC what was used on the LS as "lessons learned," along with everything else. Maybe you are referring to something else?
And apparently the Ford engineering team didn't get the DOHC memo, as they decided to use a pushrod for the Godzilla and those engines are used in F350/450/550/660. So, VERY heavy duty truck workhorses and insane block stresses I would assume. Did they copy the LS? Not even direct injection but MPFI!
To answer your comment about a 1500 with 8 lug axles being a heavy brick: Yes, it's still a 1500 as far as know. Maybe the first generation Express vans were different? The second generation I'm sure are different frames. The 8 lug seem to have a deeper frame and the body sits much higher than the 1500s.
I don't come here hating on someone because they drive this or that or want to LS swap whatever. If I can help, I'll help. I usually hang out on the diagnostic threads as that's what I see folks struggling with the most (which I feared too as a DIY-er.) Or I'm posting about food! LOL. If I don't have anything positive to say, I try to stay out. Sometimes I'm a little too comical. You gotta smile at the world and live a happy life! Life is too damn short to live hating $hit. Don't be a hater. Sorry to say this but that's how I roll.
Today I dropped off some ramps at my little brother's house. He's got a C1500 350 TBI the previous owner dropped in Jegs crate engine right before sold. It's lived 40k as a daily, but has been burning oil for a while and recently losing coolant. He had his 700R4 rebuilt when he just got it and lost OD months ago. He's been driving it like that and now got some misfire he can't figure out. He's throwing the towel. I told him to sell it and get a GMT 800, as that's what I have and very happy with them. He thought about it hard, and he really likes the OBS, so finally decided to park it and do an engine/trans swap. He's not rebuilding the old stuff. No, don't tell him the TBI will run circles around the LS; he ain't buying that story anymore.
I'm just helping with a basic VATS delete, tools and whatnot. If anything, I'm pushing him towards the 4L80e. I don't know anything about TBI-era trucks, so he's actually teaching me. I'm kinda proud of him for taking on this project honestly. Dad's certainly not a gerhead, and neither of us are, but thanks to the internet and an abundant supply of junkyard LS engines, and forums, dropping in a slightly more modern engine into an old truck is doable by the average redneck Bob or Jose without being a true gear head or spending a fortune on fancy internals. I'm not ashamed to say all of my LS engines are stock either and so will this one.
So I may start posting a bunch of questions about TBI-to-LS swaps here in a bit! Don't hate on me.
@0xDEADBEEF Yes, I read the engineers used Finite Element Modeling (FEM) and a bunch of other advanced design stuff for the LS design. For the time being, that was state of the art. You have to remember those software programs were in infancy in the early 1990s; prior to that stuff was calculated with slide rules and then those punch card early computers. I'm glad we don't have to deal with that anymore.
If you are staying with a stone stock engine, highly recomeend a complete running donor vehicle. With some slight tweaking the manifolds, Y-pipe and cats fit. One of my buddies uses the stock GMT800 air box in the squares he swaps. Uses BP Engineering harneses as well. He usually uses bone stock 6.0Ls and 4L80Es and stays DBW using a 6.5 diesel pedal. On the square bodies he uses custom built engine mounts and notches the passenger frame for compressor clearence.
As I have said before, I too have a 6.0L swapped vehicle but it mostly runs empty on long trips. Its not exactly stock but close. Ported 5.3L heads, a stock later LS6 cam, TBSS intake and headers. Its something my mom could get in, turn the key and drive to Alaska if she wanted to. I found that engine with only 70K miles. With the mileage these LS engines have on them now plan on going through it. I think my biggest issue with the LS is it is just flat overhyped. They still have their problems and I cannot stand the powerband in a heavy vehicle. I have a hard time wanting to shell out new performance SBC money to get a 250K mile junkyard LS swapped into a vehicle.
I bought the 6.0L I have dirt cheap. I had a friend that thought the crank snout was bent. Turns out that GM even has a TSB on crank pulley wobble on the LS and it was within spec. It needed a timing cover and the low mount compressor bosses were completely sheared off from the impact the donor took. But its low mileage and runs well.
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My 6.0 L swap is in an 87 G20 van and it is still backed to the TH400. Its drive by wire. I put a newer mid 90s cluster with an electronic speedo in the van, used a tailshaft housing and VSS from a 1990 TH400 and even wired up the cruise control to the factory switch. OBD2 connector slid right into the bracket for the OBD1 connector.
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PS-I have been under many of these vans from 1996 to about 2012. Unless they are a cutaway chassis they are on almost identical chassis from 1500-3500. The newer 03+ vans have a revised front frame section and engine crossmember but the rear of the frame is identical to the older vans. I have an 8 lug 1-ton chassis from a 99 in my shop and it has the same dimensions as my 97 1500 frame everywhere. The reason the 8 lug vans sit so tall is the spring package as well as the fact they run taller tires. In 97 they would have had a 235/75R15 vs 245/75R16. The 1500s are sprung so softly the thing lifts like 18" before the rear suspension lifts the tires off the ground. The leafs are 2x as thick on the 8 lugs and they as well as the front coils have a much higher spring rate. I need to get my 97 on a good scale. I have a feeling its in the 6,500 lbs ball park. It was close to 6,000 lbs when it still had the 4L60E, 8.5 10 bolt and no trailer hitch or rear sway bar. Almost every part of the suspension and running gear is now heavier.
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