72,91,92,96,99 Cadillac C-10 Pickup truck

[brad_man_72]

rear engine = crappy weight distribution?! Ask anybody that drives a porsche if 50/50 weight distribbution is "perfect".

[Chris Guthro]

LSX seems to be a better option, unless your going for creativity points..your goign to lose alot of sleep with this project i believe tho..youll be racking your brain 24/7 figuring out ways to ge tit to work

[actconstruction]

Longhorn Man, I was wondering when you'd get your two cents in. I'm glad you did. You have an excellent point about aero drag and fuel economy/ power. 23 MPG is unattainable. However, I think 15's a bit low. Especially with aggressive lowering with some rake. Actually, I made mention of the gearing way up top somewhere, but I never got any feedback, and I'm a bit stuck on that. Why would the gearing be too low for a pickup, IF the pickup weighed approximately the same as the donor car, had similar frame dimensions and sat on the ground on the original suspension from the donor (sort of, just without Electronic Level Crontrol junk). The bed is being removed and replaced with more "decorative" aluminum, and I'm dropping weight wherever I can for better starts. In other words, it would be less truck than car. It will never pull a load. I'm not being sarcastic, I'm really looking for some insight. So please, feel free to poke holes in my ideas. I'd rather someone does it on paper than to do it on the street. As far as practicality, that went out the window when I "untarped the truck". Yes, the project has changed, and yes, I should do a lot on paper. I intend to. It's just a shell and "stock" is way overrated, especially on something this old. I know, it's blasphemy to say that. As far as cool factor at the show, I think some variation of this is project should hit the nail on the head. As far as added "dead "weight" the combo only weighs about 450-500 lbs. I know this is a bit of weight, but it's like having two really fat guys in the truck. What do you think?

[actconstruction]

Originally Posted by Chris Guthro

LSX seems to be a better option, unless your going for creativity points..your goign to lose alot of sleep with this project i believe tho..youll be racking your brain 24/7 figuring out ways to get it to work

I have lost a bit of sleep already, but that's kind of the point. Like you said, creativity points. I'm trying to do something not done before. This is not a simple feat, so I'm going crazy with it. And I'm soooo sick of LS series motors. I know, "they're great", but they're in everything, even my 79 Ford pickup. And I think everybody might be overestimating the difficulty of placing the engine in the rear using the Caddy subframe. Just my opinion. It should almost "drop in". Okay, so that's a little over-simple, but it shouldn't be the worst thing ever. And I've got spare body parts and things like that, so try, and try again on this one. And I know it won't be the fastest truck ever, I already have a 95 2-door blazer with TBI 350 (don't attempt this one LOL), 79 F100 with TPI 350 (eeeasy), and a supercharged 3.8L Monte Carlo (it's a 95 with the 3.1 ripped out- not the worst swap ever). I want to do this on a budget (okay, my wife wants me to do it on a budget), but difficulty is not an issue. I have welders, hoists, lifts, and anything else I might need, including experience.

[actconstruction]

Originally Posted by brad_man_72

rear engine = crappy weight distribution?! Ask anybody that drives a porsche if 50/50 weight distribbution is "perfect".

I agree that the weight distribution issue is a bit overrated. However, where the axle sits on this truck, I don't think 50/50 would be anywhere near the worst case scenario. Also remember that Porsche has spent decades making this "work". It wasn't something that made itself happen, like they dropped the motor in the middle and voila, instant performance. Porsche's actually compensate heavily for the issues of over/ understeer that this type of balancing creates. Chevy trucks do not. That's why I thought of a bit of body roll rear steer. It should compensate for understeer on acceleration, but I'm not sure about the far more dangerous oversteer on braking. I am a very experienced driver, though, and I think I could get a lot of performance out of this setup. However, any novice drivers out there, DO NOT attempt to drive something set up this way thinking you're a NASCAR driver. You WILL burn out on the turns. As far as 50/50 distribution, I could probably estimate what type of mid-engine setup would work best using the scrap scale to work out both ends' weight on wheels. I'm leaning toward mid-engine to mitigate HP loss by driveshaft, still maintain proper (or better than stock) weight distribution, and leaving it with one engine. By using the 4l60e adapted to the 'GM metric/ GM corporate' configuration featured on the Cadillac, I should leave lots of room for any type of Small block, NorthStar, or whatever else I have the crazy urge to add. I may even just use this 4.3L I have as a mid-engine. But, I think that would be wimping out. Not sure. I'm still in the planning stages. BTW, this site is the BEST place for like-minded Chevy people, despite all our differences. I love it.

[Longhorn Man]

lower and lighter is a great start. Now look at the windshield of your truck, and then the one on any car built in the last 20 years. The angle is what we are looking at. The truck is near verticle in comparison to the caddy that donated the motor. Remember the hand out the window test. Flat is the car, verticle is the truck.
20+ MPG can, and has been obtained, and you may well nail it and get to thumb your nose at alot of us. Put I wouldn't bet the farm on it.

[Longhorn Man]

Almost forgot, the rear of the truck cab in perfectly verticle, then there is the bed that catches air, and then the verticle tailgate too. In the aerodynamic world, the rear is almost as important as the front. Picture the hull of a canoe. It slices through the water, then puts the water back in it's place with minimal fuss and turbulance.

[actconstruction]

Originally Posted by Longhorn Man

Almost forgot, the rear of the truck cab in perfectly verticle, then there is the bed that catches air, and then the verticle tailgate too. In the aerodynamic world, the rear is almost as important as the front. Picture the hull of a canoe. It slices through the water, then puts the water back in it's place with minimal fuss and turbulance.

Oh, yeah, with the engine out of the front, I figured I could plug up all the holes on the front, such as grille, under the engine compartment, etc. so that it wouldn't catch so much air in the front. Then, with the mid- or rear-engine setup the bed would be completely enclosed, except when it's show time. I think the windshield is unavoidable, but maybe a split window chop with a V-Window or something like that since I freed up a lot of head- and footroom using bucket seats slap on the floor and a newer, shorter tilt column. I know it's a truck, you know it's a truck, just don't tell the truck it's a truck. Of course, this brings up the issue of cooling a mid- or rear-engine vehicle, which I thought would have come up by now. It's far from "off the drawing board" but it's starting to come together.

[actconstruction]

Got all the non-essential systems removed and emulated where necessary to keep the check engine light off. I measured for mid-engine RWD today. It doesn't look good. Anybody know of a shorter transmission that used GM metric or GM small block bell housing? Shorter than a newer style (shorter) 4L60e that is. For such a long truck bed, there's not a ton of space front of bed to axle yoke. Looks like everything works out about right for rear engine (over the axle, not behind it). After checking out some numbers as far as front weight vs rear weight of the truck, weight distribution actually works out pretty good. I'm not the biggest fan of aluminum, but this low, low mile aluminum beasty's been good so far and parts are fairly easily obtained around here. Of course they're not like SBC parts as everybody keeps pointing out, but what is as common as a Chevy small block (the answer is absolutely nothing, and certainly not an LS motor.) We do have a Pull a Part up the road from us (the nationwide chain out of California). I do a ton of business with them and they warranty everything for 30 days. I can get a whole motor for this swap for $180.00. Not to mention I've got a spare already. As far as gearing goes, I don't think the Caddy gearing will be a problem using slightly smaller, wider wheels (done), lowering the truck a lot (done) and matching weight almost perfectly with the donor car. Phew, I was worried about weight. Anybody see a problem using deeper wheels like the ones that are on the truck, and creating stress on parts? As far as "undoability" and swapping out to a different FWD,LS4 maybe? I'm in good shape except of course for the obvious hole in the box. I think I'm going to leave the box off and sell it, so I can buy this guy's short box, which I think would be a lot cooler with the rear engine. Rear cooling is a mystery to me. So, that's where it's at. Devil's advocate, anybody? I'll take any advice into consideration except for "Don't do it, man." Now, just what am I forgetting? Guess I'll know when I get to that part.


EDITED BY STAFF: Please note that you must be a supporting member to post classified items. This includes but is not limited to What Its Worth, Want To Buy, Want To Trade, and For Sale. Please consider supporting the forum by subscribing. Further information on the subscription levels available are located here

If you need any further assistance with that please contact any Admin for help.

[Jonboy]

Since they used the 4100 (4.1) in the full size RWD Deville in the early 80's, why not keep the truck RWD, and use a 200R4 with the split bolt pattern, and do the swap that way? I would imagine (just a guess) that the bosses for a RWD mounting are cast in as well. Those DeVilles used everythng from a 425 & 368 (think 472/500), to the 4100, and finally a corporate 5.0, so a trans from one of those or an intermediate size RWD car should net you the 200R4.

[actconstruction]

Originally Posted by Jonboy

Since they used the 4100 (4.1) in the full size RWD Deville in the early 80's, why not keep the truck RWD, and use a 200R4 with the split bolt pattern, and do the swap that way? I would imagine (just a guess) that the bosses for a RWD mounting are cast in as well. Those DeVilles used everythng from a 425 & 368 (think 472/500), to the 4100, and finally a corporate 5.0, so a trans from one of those or an intermediate size RWD car should net you the 200R4.

That's an excellent idea!!! I feel a little bit dumb for not thinking of it. The gear ratios are almost identical between the two transmissions, closer than the 4l60e for sure. There are many other cars with that transmission as well. I just got an interchange on it. Many of them came with SBC and corporate bolt patterns(Dual pattern). It should hold a couple hundred horsepower just fine. Then I need to swap out the differential on the truck. It even meets the criteria of having a lot of swap options in the future. Now to figure out the sensor add-ons to pull the data required to run everything the way I want it. I don't have any transmissions that foot the bill here and weather looks a bit nasty until Friday but I know where some candidates are. Can't wait to get up there and work it all out. Fingers crossed for tomorrow. Thanks, Johnboy.

[D13]

The FWD trans pattern is different than the RWD pattern. 2 different blocks. Since the 4.9 was not used rear wheel (by then they went to the 307 Olds and 350 Chevy in the D cars) the bosses probably aren't there.
If you had a 4.1 out of 85ish brougham it would bolt up to 2004R. But those motors overheated and ate rear main seals, which is why they were replaced with the 307 Olds.

It does seem that an adapter plate and some drilling and spacing on the flex plate would let you bolt it to a Chevy pattern pretty easily. Then all that would be left is the motor mounts.

Personally I've seen enough FWD in the bed conversions. I think a FWD truck would be neat. How about AWD using a stretch drive shaft? You'd have to lose some weight if you were going to drive it hard... but it's be cool.

[actconstruction]

Originally Posted by D13

The FWD trans pattern is different than the RWD pattern. 2 different blocks. Since the 4.9 was not used rear wheel (by then they went to the 307 Olds and 350 Chevy in the D cars) the bosses probably aren't there.
If you had a 4.1 out of 85ish brougham it would bolt up to 2004R. But those motors overheated and ate rear main seals, which is why they were replaced with the 307 Olds.

It does seem that an adapter plate and some drilling and spacing on the flex plate would let you bolt it to a Chevy pattern pretty easily. Then all that would be left is the motor mounts.

Personally I've seen enough FWD in the bed conversions. I think a FWD truck would be neat. How about AWD using a stretch drive shaft? You'd have to lose some weight if you were going to drive it hard... but it's be cool.

Yes, I've worked out that it needs exactly 1" extra spacing and of course adaptation of the actual bolt pattern. Then, the flywheel needs to be redrilled and checked for bal. The torque converter from the 4.3L 4L60e even has proper stall and stiffness to match the 4.9L. The final drive would have to be used to compensate for WAY different gear ratios. Not sure about that little pain in the ass that often gums up the works on these jobs, the starter.
AWD would be cool, but too many down sides and utter lack of experience on my part. I will drive it hard, I can't help it.
We do need to keep in mind, as you hinted at, that not all 4.1/4.5/'s are the same as the 4.9. The bosses won't be there. However, I think it would be erroneous to say "FWD bellhousing". It seems this wouldn't be accurate at all. This is the information I'm working from as far as the metric pattern goes:

GM metric pattern
Also called the GM small corporate pattern and the S10 pattern
This pattern has a distinctive odd-sided hexagonal shape.
GM 2.8/3.1/3.4 L V6 (also used by AMC)
Buick 3300/3800 V6
Cadillac 4.1/4.5/4.9 L V8
Isuzu 3.5L DOHC V6
AMC/Chrysler 2.5L I4 found in Jeep Cherokee, Comanche, Wagoneer, CJ and Wrangler and Dodge Dakota
GM Iron Duke/Tech-4 2.5L I4
GM "122" 1.8/2.0/2.2 L I4
GM 5.3L LS4 V8
If I'm wrong, somebody PLEASE correct me.
This is the pattern that was sold to Jeep with the early 60 degree V6's and then bought back in the 70"s. It is also one bolt hole and a starter position different from the "Northstar pattern."
There are too many in-bed FWD over rear axle conversions, aren't there? I would love to make the truck FWD. The frame is about 8 inches too skinny in the front, though. I'm not sure exactly how to solve that problem without massive alterations to the truck. And we're not going there. Not yet.

[actconstruction]

Shazam! I'm off to get a 6L80! What luck!