LX Forums Forum banner

6.1 into 87 Dakota

85K views 109 replies 13 participants last post by  Glen440 
#1 ·
I'm in the process of putting a 6.1 hemi into a 1987 dodge dakota. I bought it back in june. It was a 3.9 v6 with a 904 transmission.
I'm going to just do an engine swap and get it driving before doing a transmission and rear axle. I have a 727 and dana 60 from another car. Really want overdrive so maybe an a500 or 518.

Its proving to be a bit more fabrication than I originally anticipated. I'm doing this in my driveway as I have my original project 39 chev inside. I need the dakota frame for that car but have decided to drive the truck around first.

I have made engine mounts on the engine side to mate to the original v6 mounts. If I do this again I will make new mounts on the crossmember as they are taking up valuable header space.

Engine needs a spacer between the transmission as the conversion flexplate pushes the torque converter all the way in the transmission. I made a 1/8 spacer to start.

Brake booster is too big. Valve cover fits barely with no coil pack. I have not decided what way to go, smaller booster, hydro boost or manual brakes.

I thought I could fit an exhaust manifold but the passenger side is only 3 inches from the upper control arm. The downward angled exhaust is a huge problem. I see why the old bigblocks fit better. I had a 440 A body and F body, they had way more room. I just started on headers last weekend. I made my own header flanges and bought the cheapest sbc header kit I could find. Its a challenge as all the bends are random and not true mandrel as the bends are smaller. The aluminized mild steel tube is hard to see while tig welding from whatever in it burns. I may just mig them as I was tacking with mig in the car. I do not have a tig at home. Stainless was just way too expensive for my first try at headers. It this goes under the chev the engine needs set back a foot so would need new ones anyway.

Fuel system is an external fuel pump with corvette fuel filter as the regulator. Tank has baffles so I put a fitting in the bottom and return in the original pickup.

Cooling is unknown until I put the engine in for last time and rad support on. Its gonna be a tight fit.

Computer is a megasquirt gold box which came with a wiring harness. Trying to find a spot for it. May put it behind glove box so you open the door to access.

I modified the stock throttle body to run a cable, it will also do throttle pressure for the transmission. I modified a ford iac motor for idle control.

I'll post pics when I figure out how maybe from my phone.
 
See less See more
#27 ·
Its 24mm according to what I can find online for replacement master cylinders. I don't think the bore size is a problem. I also don't like the angle of the pushrod to the master.
I cannot find anything on whether these trucks came with manual brakes.
 
#29 ·
Last weekend rained so I did not get much done. I got a full day in today.
I got the fans installed on the rad, rad hoses are a tight fit.

I got the exhaust done to the mufflers. I used some cats off a challenger. I went with 2.5" with dynomax super turbo mufflers.

I think I will do some wiring tomorrow and maybe cold air intake.



 
#33 ·
Nice work documenting this swap. I always wanted to see someone do a GEN III Hemi in a 87 Dak. The core support is much more shallow compared to the 91 and up Daks.. Great job with all of the fabrication you've done. Have you made any further progress thus far. Can't wait to see the finished product.
 
#36 ·
I'm gearing up to continue working on the dak. Was too busy last year. I'm switching the efi controller to the holley terminater x that was just released. It can go under the hood. I have no room inside the truck.
I just have to swap some connectors as the holley has the newer ones.
Going to come up with a way to prime the engine. I don't like the flexible upper rad hose so might make one out of stainless tubing.
I have a few things that need to occupy the same space so its getting tight up front.
I'm hoping to have it running in April.
 
#37 ·
Keep up the good work. You would create quite a bit more room by swapping the rad core honestly. Either way you go, you are accomplishing something most people haven’t tried as of yet.


Sent from my iPhone using Tapatalk
 
#40 ·
I don't really like the idea of a bed mounted rad. I also don't want to change the front.
If I have to I will modify an aluminum rad and put the upper rad hose where I want it. I'm not against modifying the rad support, I do need room for the ac condenser.
If I move the battery it would solve the problem I have right now. I'm going to try to run the cold air on the upper rad hose side first and see if I can make it work.
I will do things the harder way if I think its better.

DBL.DWN what are you building?
 
#44 ·
I have made some progress. Tail pipes just need final welding, gas tank is in for last time, cold air tube is done, holley terminator efi is almost completely wired. I had it powered up to figure out the tps wires. It should be running in the next couple weeks. I want to go over some stuff before I drive it.
 
#45 ·
I fired it up today, started right away. I still need to finish a few things. Just wanted to hear it run.
Gas tank is not venting, have to figure that out. Just have to clean up wiring. Cold air intake is loud.
I used the dakota voltage regulator to run the alternator. Only had it run for a minute. I made a timing map based on a ls3.
 
#46 ·
I had it running for 15-20 min today. I'm going to concentrate on getting it ready to drive now. It runs good, no leaks, everything works. I'm fighting the iac a bit, must need its parameters changed a bit. I'm using a ford 2 wire pwm, it was the easiest way with the stock drive by wire throttle body.

Now that the tune is happier at idle the engine is really quiet. I'm going to work on putting the truck back together and going over the brakes. Should be driving sometime in june.
 
#47 ·
I'm really close to finished. Having an issue with the brakes, front are sticking. They are holding pressure when you get off the brakes. It has new calipers and flex lines, if I crack the bleeder or even the line at the flex line they release. I'm waiting for a master cylinder. I wanted to eliminate the factory proportioning valve and replace with an adjustable anyway so might run new lines.

I picked up a 46rh transmission for the future. I decided it was the best route so I do not have to modify headers and run a big computer to go 8 speed. They make a small programmable computer to run overdrive and lockup.
I can rebuild 727's so its just learning the overdrive unit. Just have to decide on rear end. Its looking like the rest of the drivetrain will be next year.
 
#48 ·
For a rear diff I’m sure you can find 9.25’s at the recking yards fairly cheap. If you grab something from 03/04 they will come with rear disc brakes that are fairly good as well. Nice work on this build. I’ve considered doing something similar in my 02 Dak. Times have changed and I’ll be going full race with a Gen3 Hemi in my Race Dak.


Sent from my iPhone using Tapatalk
 
#50 ·
I was not impressed with the 9 1/4 in my 03 dak. Posi was too grabby around corners then it broke it. Carrier is not rebuildable.
I have 5 bolt so it's either 8.8 or I do have a B body dana 60 with 4.10 track lock and strange 35 spline axles. Its 2 inches narrow which is fine.

I'm close to having the air conditioning done. Just need some different angle fittings. I welded Male fittings to a factory condenser.
 
#51 ·
I finally drove it today. It runs good. Was a short 10 min drive. Going to have to go out in the country and get some tuning through the rpm range and throttle positions. I might need to get it on a chassis dyno for that.

So far its close to what I was after, quiet, smooth and lots of power. Brakes will take a bit to get used to, I have not had a manual brake car in 10 years.
 
#52 ·
I spent a lot of time trying to tune in gear idle. The torque converter drags the engine down alot.
The iac was going nuts trying to fix it. I had to set idle and iac position with it in gear and let it idle higher in park, so
No control in park except idle screw. I would have iac position at 5% then in gear would be 85% then would surge because it could not raise
Rpm, it also uses timing so that would jump +,- 10 degrees.

I thought the V6 converter would be loose behind this engine.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top