69 Camaro TH350 to 4L80E swap - Cam, Converter stall and cruise specs

[mdavidthomas]

I recently purchased my first 1969 Camaro. I have wanted one since I was 15 and now I am 52. The car was built for drag racing and has the following specs:

Motown 400 SBC block with 4.125" bore
Scat 4340 3.75" stroke crank "
Eagle 6.00" H Beam rods
SRP 16cc dished pistons for ~10.25:1 compression ratio
Brodix STS 215 T1 heads with 64cc combustion chamber with 2.08/1.60 valves, mechanical roller springs 1.550" diameter, 255lbs @ 1.9550" installed height, 610lbs open, 0.700" max lift
Comp Cams 252/258 duration @ 0.050", 0.630/0.630" lift, 106 LSA, Billet Steel Mechanical Roller 0.900" base circle cam
Isky Red Zone Mechanical Roller tie bar lifters
Comp Cams Pro Magnum Roller Rockers 1.6 Intakes/1.52 Exhaust
Edelbrock Victor Jr. Single Plane Intake manifold
AED 750 cfm 4150 carb
1.75" long tube headers
PTC 10" Torque converter - not sure on stall speed but guessing 3800-4000 rpm
TH350 Transmission with Full Reverse Valve Body
Moser 12 Bolt Rearend with 3.73 gears
275/40/17 Drag Radials

The car has about ~1000 miles on a 2005 build. Seems to be a strong car but I am looking to do more cruising than drag racing; however, I don't want to give up all the power. I wanted a 4L80E overdrive and maybe a Holley Terminator Max X 4150 Carb style fuel injection unit. Along the way I figured I would route the exhaust out the back instead of the dumps under the car and purchase a hydraulic or mechanical roller from Comp Cams 242/[email protected]" 0.570/0.576" lift, either LSA 110 (Extreme Energy) or 113 (Extreme Fuel Injection) cam and a Edelbrock Performer RPM style intake manifold.

I must state at this point I am totally confused at what to do with regard to the transmission/Stall speed/Cam. The car turns about 3000 rpm at 60 mph in third gear currently and with the addition of an overdrive of 0.75 it will turn ~ 2200rpm. If I change to the Comp Cam 242/248 grind, it states you need a 2800+ stall with it's 2500-6800 operating range. This means the stall speed will be below the overdrive cruising speed at 60 mph of 2200 rpm in overdrive. I could drop to the down to a smaller cam which is a 230/236 duration cam that has an operating range of 2200-5800 which calls for a 2500+ stall speed; however, I think this cam will drop power from ~600 Hp to ~450 HP along with the other changes and I am still over the cruising rpm rating. I know the 4L80E could be programed to hold third gear through a higher RPM and I have read you could lock up the converter immediately in overdrive but I am unsure what to do at this point. I am trying to avoid any bucking or surging while cruising in overdrive. Any suggestion greatly appreciated.






mdavidthomas