70 Shortbox Chevy 2wd considering a GM 3800?
 

Hi there this is my first thread. been coming to the site for years though. As the title says I have a :chevy:70' Fleetside Short Box:chevy:. I would love to put a motor in this truck that would make it do a wheelie but with fuel prices steadily rising im leaning more on the practical side of things. I found a GM 3.8 V6 out of a 96 Pontiac van for $150. It has 150,000 miles and runs great. Comes complete with computer and all (Craigslist Find). Also found a complete Super Charger for this motor for $100 (Also a craigslist find) Has anybody ever done this motor swap in an old pickup like this? If So was it easy? What needs to be done with remapping the computer? Im going to pair it up with a Post 87' 700R4 cause i heard the valve body was stronger then? Im hoping for north of 20mpg. Is this even plausible? Also side note is it difficult to switch over to power brakes from all drums. Thanks for all the advice everyone.

PS any mod suggestions or your favorite mods for this Gen body style are welcome to.


http://i154.photobucket.com/albums/s...et_1549_-1.jpg

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

wow need to reduce that picture down a tad.

For starters van engine is a FWD going to need special mounts to get it to fit different mounting points then the RWD f body engine which are closer to what you would want. Need to use a trans from a small 6 as well v8 tranny wont bolt up. FWD engine has the manifold pointed the wrong way no big deal it fits either direction but the SC intake can only go one way and work. Since you got some room to work with the truck engine compartment and you need to fab custom mounts anyway I could see it being able to be run with the throttle body pointing toward the firewall just would require custom duct work. I know pople that have left the stock non sc ecm and ran a sc on there 3.8l fwd's i recommend getting an ecm made for a sc engine as well as the correct knock sensor.

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

it will need more tha jus tha s/c to make that motor run...goggle Top swap & you see what i mean. that lil 3.8 will catch h&^l tryin to pull that truck around

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

A member on the Chevytalk board installed a Buick turbo engine in his truck and was extremely happy with the performance. His install was a little easier than yours because he started with a RWD engine from a G-body, but I don't think you will have any problems you can't overcome. You will have a huge amount of room to work around the engine.

For a transmission, I am thinking maybe 4th gen Camaro/Firebird. S-10 4 cylinder and 2.8 V-6 transmissions will also bolt up, but the F-body came stock with a 3800.

Ray

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Would you happen to have a link to that build? I would love to talk to him and see what he had to overcome to make it happen.

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Unfortunately, no. This was a few years ago on Chevytalk and the search over there is kind of flaky unless you can enter an exact text string, which I can't.

Ray

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Forgive me if this is a stupid question but what body styles do the term F-body apply to? I know it would be better to put a rear wheel drive motor in but the only difference is the intake correct?

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

F-body is Camaro/Firebird. Besides the intake manifold, the mounting hole locations on the block are different between FWD and RWD. Since you will have to fab your own mounts anyway, this shouldn't cause you too much extra work.

Ray

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Would I be over-torquing that motor in something as heavy as that 70swb?

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Even a junkyard 350 will net you better performance and be a much easier install. That v6 just isnt going to make the torque needed. The engine mounts are going to be a complete and total pain in the @ss to get right. Your going to need the harness and computer reworked. That engine is designed to work with a computer controlled electronic transmission. Theres not a chance of getting anywhere close to 20 mpg because you will be working the engine fairly hard most of the time. Maybe downhill in neutral with a tail wind.

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Bingo. Your truck isn't going to get north of 20mpg even if it's being towed. Engine displacement really doesn't have as much to do with gas mileage as people think it does...

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

I 3rd that. Going efi is a good step in gaining mpgs. But that lil v6 won't do a lick of good in that truck. The only v6 i would even considder using would be a 4.3. It will bolt in place of an sbc, but doing an efi swap like a tbi or tpi swap is going to net you better results due to the power to weight ratio, which is why that 3800 would be too over tasked in a heavy truck
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Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

My Dad's '64 C10 is getting 18-20mpg with a tko600 tranny and a 350 with vortec heads and a Performer RPM Airgap. Cam is 219 @.050 on the intake side. That would meet your milage goal and have MUCH more power. FWD engine layout does not make for an easy rwd swap. I'd just build a tame 350 or even a 305, toss an OD tranny behind and enjoy 20+ mpg, cheap parts and the easy swap. I'll bet you could score a good running 305 with roller cam and one piece rear main seal for practically free.

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

If yoy were lookin to go the 305 route i got one from an 88 firebird that you could have if you lived closer
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Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

I can be done and yes the motor did get great mileage in the F-body cars, but you must consider that the F-body is quite a bit lighter than the truck, and most importantly the aerodynamics are FAR better than the truck will ever be.

That said, it's going to be a lot of trouble for a result that feels underpowered and doesn't get that great of fuel economy.

Instead, look into a TBI 305 or 350 with a 700R4.

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

Thanks for all your thoughts guys. I think im going to scrap this idea all together. It sounded good on paper but weighing out all the options its a lot more work and it adds a lot more complexity to a project that ultimately I want to remain very simple. I just ran into a sweet deal where im getting the engine of my choice built for free (i supply the parts of course). So think i might switch to the other direction and go for HP in stead of MPG... You only live once right?

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

ok as above your idea is good but you need a little help..
the van is fwd. get a f body (camaro/ trans am) 3.8(3800)
and the tranny.
I'd if you don't want the wire'n nitemare
get the 3.8 buick(same engine) out of a g body or b body (get the buick it has the dissy in the front, the chevy is dissy in the back and is a 229 the buick is 231)
get the mounts frame stands all of it..
the engines will have a 2brl carb , unless you get a t type or g/n 3.8
it bolts into the truck use'n the sbc frame stands to mount the motor mounts to. (you'll have to drill a few holes in the frame stand(trucks)
other than oil leaks they run forever..
if you wand efi and spark control. the latest f body you can find, some had sticks..
but remember the tranny is at an angle to fit under the floor of a f body..
and may cause fits when installing under the truck..
good luck..
FYI
IF YOU CAN FIND A 3.8 Q JET INTAKE the older 3.8 will get the same mpg as the efi one. within 1mpg.
untill you hammer it.. then all bets are off..

a 2nd gen f body inline 6 will get you better mpg. as it makes more ft lb down low..
but the 3.8 will run away from it when you slam the hammer down

Re: 70 Shortbox Chevy 2wd considering a GM 3800?
 

No, it's not a chevy truck they are talking about, but I would go to www.bruntonauto.com. Look at the installs of the 3800 with supercharger. They offer a plug and play wiring harnes to mate the 3800 Park Avenue with blower to a manual transmission. I keep thinking about it for one of my trucks but my kids keep taking all my money. Always wanting something.........food, clothes, shelter, it just never ends.