'85 LT1 TH400 conversion
#1
Melting Slicks
Thread Starter
'85 LT1 TH400 conversion
Posted over in C4 Tech as well, but thought the actual racers here might appreciate this.
For those who know this car (Blackbird), it's our shop "test bed" for different things. I decided to make a dual purpose streeter out of it. Swapping the heavy-assed Center Line wheels for some Greg Weld Motorsport big 'n littles, the decision was to make it more drag race oriented. Pic as it looks with its new wheels:
For power, I decided to try something a little different: put a later style LT1 (the one from my '96) into my '85 to replace its very tired L98. The '85 already had a carb conversion done (with adjustable plate nitrous, of course), so we swapped to a carbed intake with MSD billet distributor:
Pulled the 4+3 manual trans in favor of an automatic - decided to use a TH400 for reliability over a 700R4 (and a 3600 stall nitrous converter to help launch capability). A conversion bracket was fabricated to attach to the existing C-beam:
Closeup of bracket:
Did a little tunnel surgery to fit the B&M shifter, to help it fit within the confines of the stock console. Here's how we did it:
The result with the console back in place:
A closeup, also showing the dual function switches for the cooling fans and electric water pump (down for "auto"-keyed power, up for "manual" battery hot for between rounds cooling):
All that's left is to fabricate the gauge cluster for the Auto Meter Pro Comp UltraLites.
(and maybe drive the damned thing one of these days!)
For those who know this car (Blackbird), it's our shop "test bed" for different things. I decided to make a dual purpose streeter out of it. Swapping the heavy-assed Center Line wheels for some Greg Weld Motorsport big 'n littles, the decision was to make it more drag race oriented. Pic as it looks with its new wheels:
For power, I decided to try something a little different: put a later style LT1 (the one from my '96) into my '85 to replace its very tired L98. The '85 already had a carb conversion done (with adjustable plate nitrous, of course), so we swapped to a carbed intake with MSD billet distributor:
Pulled the 4+3 manual trans in favor of an automatic - decided to use a TH400 for reliability over a 700R4 (and a 3600 stall nitrous converter to help launch capability). A conversion bracket was fabricated to attach to the existing C-beam:
Closeup of bracket:
Did a little tunnel surgery to fit the B&M shifter, to help it fit within the confines of the stock console. Here's how we did it:
The result with the console back in place:
A closeup, also showing the dual function switches for the cooling fans and electric water pump (down for "auto"-keyed power, up for "manual" battery hot for between rounds cooling):
All that's left is to fabricate the gauge cluster for the Auto Meter Pro Comp UltraLites.
(and maybe drive the damned thing one of these days!)
#2
Race Director
Real nice work, Robert...should be a good runner...I dropped my converter off at FTI today for a refresh and my 400 at Ken's in Orlando to get freshened up as well...
#4
Team Owner
Interesting choise of carbs. Nice conversion.
#5
Safety Car
I was going to say something about that carb.If you can get one of those to work on a chevy more power to you.
Change to a holley and watch the motor come alive.
Change to a holley and watch the motor come alive.
#7
Race Director
Except for my Camaro...the Holley 750 double pumper was awful and the car came alive when we put in an Edelbrock...go figure...
#8
Melting Slicks
Thread Starter
As far as cutting the tunnel... this was a 4+3 manual trans car, so the tunnel on the LH side protruded in for the shift linkage (really stupid design, IMO), which may have interfered a bit. That tunnel section was removed primarily for the shifter mounting, but the bellhousing cleared with no trouble. An automatic equipped model would likely need no tunnel mods, save for lowering an aftermarket shifter.
No pics of the top of the C-beam, sorry (plenty of clearance, tho)
Last edited by RacerX70CC; 03-25-2009 at 08:39 AM.
#9
Instructor
So I'm bringing this up from the dead, if you have any information about how you got VSS to work I would like to know aswell since I have an 86 4+3 car that I'm going 400 on but will be turbo LS.. Anything to make this a more understood process would be great since I will be starting the project in a couple months. Thanks in advance
#10
Safety Car
So I'm bringing this up from the dead, if you have any information about how you got VSS to work I would like to know aswell since I have an 86 4+3 car that I'm going 400 on but will be turbo LS.. Anything to make this a more understood process would be great since I will be starting the project in a couple months. Thanks in advance
Once you go to a 400 you will be changing the car alot and it will become a nice ticket machine,I was running over 700 hp and after awhile I pulled it off the street .I also installed a 4 link.I also had to install a universal shifter and a 5500 tq converter.
#11
Instructor
I dumped it on mine when I went to a th 400 .I bought an electric spedo that I got from Summit racing ,it works off magnets on the drive shaft.
Once you go to a 400 you will be changing the car alot and it will become a nice ticket machine,I was running over 700 hp and after awhile I pulled it off the street .I also installed a 4 link.I also had to install a universal shifter and a 5500 tq converter.
Once you go to a 400 you will be changing the car alot and it will become a nice ticket machine,I was running over 700 hp and after awhile I pulled it off the street .I also installed a 4 link.I also had to install a universal shifter and a 5500 tq converter.
#12
Safety Car
I have to look up the spedo at Summit but this may give you a clue.
http://www.summitracing.com/search?S...c%20spedometer
It's just a game of money!!
Last edited by REDC4CORVETTE; 01-14-2015 at 06:04 PM.
#13
Instructor
http://vettaid.com/ReplacementGauges...ePackages.aspx
I have to look up the spedo at Summit but this may give you a clue.
http://www.summitracing.com/search?S...c%20spedometer
It's just a game of money!!
I have to look up the spedo at Summit but this may give you a clue.
http://www.summitracing.com/search?S...c%20spedometer
It's just a game of money!!