I recently rebuilt my 1275 (has around 1000 miles on it now) and was having lean issues changed the needle from a BBW to a BDK, checked fueling with a colortune and have a nice blue flame when idling and holding at various RPM's. The issue I am having is since I changed to the BDK if I blip the throttle it wants to die, sometimes I can save it by continuing to blip the throttle and if I cruise for a bit it will be back to normal, if I blip the throttle to downshift coming to a stop it will try to die. I did not have these issues with the BBW.
Some build info
1275 overboard to +40 (so 1310?)
minispares evolution001 cam
minispares evolution dizzy, the one they recommend for the cam
MED stub stack with foam filter
Hif44 with yellow spring (putting the red back in makes the issue worse it seems)
Minisport 1.3 roller rockers
Minispares vernier timing set (set close to 107 per their recommendation, best I could get was 106.5 ish, I did the math multiple times then averaged what I was seeing).
stock head with larger inlet valves, and minispares double springs
Prior to swapping the needle I had bottomed out the enrichment and was still having issues running lean, when cruising on the highway in 60 ish weather my coolant temp would rise to 195 and I would need to use the heater to keep it down in the 180 range (I have a 167 degree thermostat). Other than the temp issues on the freeway overall driveability was good. plugs were white in color, along with the temp I figured I was leaning out around 3000 - 4000 rpm.
With the BBW the car runs amazing aside from the wanting to die after blipping the throttle. I rechecked my timing and had my wife hold it at 4000 RPM and verified im at 32 degrees. I have verified the dash pot is full, I use the SU dashpot oil in it. I sprayed around the carb with wd40 as well to see if I had a vacuum leak, the revs did not increase.
Any thoughts on what I should check next?