BBC Turbo 400 to LT4 T56
 

I have sold the complete driveline from my 71. Radiator to rearend , pan to carb ....gone. It will help cover a small portion of the cost of the conversion. I may regret that decision one day.

....There is no turning back.

Re: BBC Turbo 400 to LT4 T56
 

The victim.

Re: BBC Turbo 400 to LT4 T56
 

Made a little headway. Got the trans, seat, carpet and steering wheel out too.

Re: BBC Turbo 400 to LT4 T56
 

After a couple tries I got the motor sitting in place and harness laid in. I built a pair of custom motor mount brackets to get it sitting where I want. Good news is I can use the factory oil pan. Bad news the oil cooler hits the crossmember so it has to go. I couldn't find anyone building a remote oil cooler set up for this oil pan yet so I cut the stock one apart and added some fittings to remote mount something later.

Re: BBC Turbo 400 to LT4 T56
 

.....Feels like I am talking to myself.
I've got a factory high hump so I am lucky there. Time to molest it .
Yaaa !, the wiring harness is long enough, I can hide the phone book ECM under the seat! Just need to figure out a grommet set up for the harness to come through the floor

Re: BBC Turbo 400 to LT4 T56
 

Took a knife to the harness. One wrong move and it can spell disaster.The GM tape that holds it together is high quality! Changed up the corrugated covering to a smaller weaved cover and was able to hide some of the wiring

Re: BBC Turbo 400 to LT4 T56
 

Needed a way to plug the water pump outlet for the oil cooler so I took the OEM fitting and welded a flange on to it so I could add a add a temp sensor. It's super tight. I just managed to fit it then there.

Re: BBC Turbo 400 to LT4 T56
 

Hopefully the Dakota dash will connect seamlessly to the ecm and save me a few wiring headaches.

Re: BBC Turbo 400 to LT4 T56
 

Very Nice truck and extremely clean build!

Re: BBC Turbo 400 to LT4 T56
 

I'm in for this build. Very cool.

Re: BBC Turbo 400 to LT4 T56
 

if you've got the bim module from dakota, its a super easy install. Instead of using the plug in from the obd2 connector i purchased the same style connector from radio shack and hard wired them from the back of the obd2 to the bim module. Much cleaner look. 1 thing to note though is that you must unplug the gauges when using hp tuners. It won't load up as it recognizes the split in signal. Took me awhile to figure that one out....

Re: BBC Turbo 400 to LT4 T56
 

I do have the BIM module. Good tips . Thanks.
Drive Junkie supplied the front serpentine set up. The fit and finish is awesome. I went with it because I prefer the blower to have its' own belt. I am scratching my head how to connect the 2 wire ALT feed that Gm supplies in the engine harness. The alternator supplied by Drive Junkie is a one wire set up.

Re: BBC Turbo 400 to LT4 T56
 

Nothing exciting today. I extended the fuel pump and fuel pressure wires and got them run to the back along with my taillight harness. Modified my trans crossmember to match the new location of the mount for the T56 magnum. Set the new rad in to get a feel for how much room I 'll have for the shroud,fans and air intake.

Re: BBC Turbo 400 to LT4 T56
 

Not much to report. Moved my trans mount and got it bolted back in. It ended up moving forward a couple inches in relation to the old T400 location.

Gm warns that the LT4 doesn't create much vacuum so I have been messing with a hydroboost from a 03 Mustang trying to determine if I can make it work in the truck.

Re: BBC Turbo 400 to LT4 T56
 

Astro Van ones work well, PM LS1nova71 Eric is a bottomless pit of info.

Re: BBC Turbo 400 to LT4 T56
 

Cpp makes a real nice hydroboost kit called street beast I have it on my 71 with ls swap.

Re: BBC Turbo 400 to LT4 T56
 

Hydroboost from cpp

Re: BBC Turbo 400 to LT4 T56
 

Thats going to be one wild ride!:metal:

Re: BBC Turbo 400 to LT4 T56
 

This badboy arrived today.
Wavetrac with 3.50 gears and 35 spline

Re: BBC Turbo 400 to LT4 T56
 

Nice that should hold up to the 650 hp !

Re: BBC Turbo 400 to LT4 T56
 

Out with the old and in with the new. No drama. I like when that happens.

Re: BBC Turbo 400 to LT4 T56
 

That's some great quality parts going into a slick truck.

Re: BBC Turbo 400 to LT4 T56
 

I unboxed and bolted up the headers. We got them from Ultimate. They were designed for a 67-69 Camaro LT4 swap. They work pretty well. I had to massage the passengerside engine pedestal a little bit but other than that easy peasy. Tons of room to slide them in.
The collector does hang about 1/2 inch below the frame but I can live with that.

Re: BBC Turbo 400 to LT4 T56
 

Got the 03 Mustang hydroboost adapter plate made.
....hope it works.Just need to build the linkage.

Re: BBC Turbo 400 to LT4 T56
 

Mounted up the new condenser. Now time to figure out the heat exchanger mount for the supercharger.

Re: BBC Turbo 400 to LT4 T56
 

I like the way that sounds.

Re: BBC Turbo 400 to LT4 T56
 

I was dreading cutting the firewall and mounting the clutch master. Getting the inside of the firewall smoothed out was a bit if a challenge but it worked out not to bad in the end.
My Mustang hydroboost adapter worked like a charm. Both the clutch and hydroboost linkages are done

Re: BBC Turbo 400 to LT4 T56
 

I plan to tackle the heat exchanger and dbw pedal this week.

Re: BBC Turbo 400 to LT4 T56
 

The stock oil cooler had a conflict of space with the front cross member. The cross member won out. The remote set up arrived. Not sure it will fit up front. It may have to go under the box on the drivers side.

Re: BBC Turbo 400 to LT4 T56
 

Had a pal come over and we tweaked the existing exhaust set up to the LT4 headers. Couple beer and we had it done.
The low profile couplers form Ultimate seem like a quality pieces. Hope they seal well.

Re: BBC Turbo 400 to LT4 T56
 

Well I didn't get to building the mount for the drive by wire gas pedal but did get the heat exchanger mounted and have a bracket designed to mount the oil cooler up front. AFCO custom built this dual pass unit for me. I've modified the hood latch brace a little bit to make room for it. While I have the grill out I'm going to cut out around the headlight for fresh air for the intake/air filter.

Re: BBC Turbo 400 to LT4 T56
 

This must be the most boring 650HP LT4 build on the interweb. I generally don't talk to myself this much!:alky:

Re: BBC Turbo 400 to LT4 T56
 

Coincidence I'm sure. Not my style, but sure are some nice parts there. Keep it up.

Re: BBC Turbo 400 to LT4 T56
 

That's looking great.

Re: BBC Turbo 400 to LT4 T56
 

Chopped a hole in the rad support today to supply cold air to the filter. Might have gotten a little carried away with the size of it . Ol well..
Rear brakes showed up finally. Maybe I can get it on its' wheels again tomorrow and then do some measuring for a new 4" driveshaft.
Started researching rad hoses. GM decided 1 3/8 would be a good idea off the water pump. Might be tricky to find something to work well.

Re: BBC Turbo 400 to LT4 T56
 

loving it!!!!
This sucker is gonna be killer

Re: BBC Turbo 400 to LT4 T56
 

So jealous...

What t56 transmission did you get and from where?

Re: BBC Turbo 400 to LT4 T56
 

I purchased the trans from my local GM dealer. They offered to match the best price I could find on the web. It's the magnum with the close ratio.

Got the oil cooler mounted. It took some custom brackets as it was a tight fit. Plumbing was a breeze. These push lock fittings and hose are so easy to work with. I have a oil thermostat in line. It opens at 180. The fans are controlled by a thermo switch as well and they come on at 190.
Rummaged threw a bunch of rad hoses at the local parts store. Grabbed a couple and was able to get the lower hose figured out. It was the first one I grabbed! I thought I would try to carry on my luck by messing with the AC compressor and attempted to connect a couple fittings to the manifold but no dice. .....They hit the frame. I'll have to sleep on that problem.

Re: BBC Turbo 400 to LT4 T56
 

You will have to tell us how you like driving that combo when you get it done! When are you hoping to have it ready for the road?

That's cool that your GM dealer did that for you. Do they do that a lot? I've never heard of that. I wouldn't imagine they get that much better pricing on them than we would unless they are a frequent shopper.

You need to post up some pics of your garage/shop! It looks like a nice place to be! I love the color of the floor!

Re: BBC Turbo 400 to LT4 T56
 

I am fortunate to have a bit of a mancave.


Got the brakes finished up.(by that I mean mounted) A bit of a glitch with the axle offset. Moser suggested the brake package to go with from Wilwood. I followed their instruction and purchased the Wilwood kit but the calipers didn't center up on the rotors. I got the wrong spacer from Wilwood or Moser messed up the offset. Option A was to pay for new spacers and shipping that cost more than the spacers or option B build shims. I went with B. The aluminum shim is pictured in the 1st pic. The 13" brakes still look a little small on a 20" wheel but the cost to upgrade to bigger just didn't make sense to me.