disapoining et

younggun2.0 said
sounds like we have established a couple things here.

1. the carb is wrong.

2. you need some solid info about your tune.

Here is what I would do. I would swap on either a new or known good running 750 dp. with mech. secondaries.

I would then address timing. I would start with the cam. i would pull the timing cover and degree the cam. I would make sure it wasn't installed retarded. i would set it up per the cam card.

I would then bolt it all back up and set your initial at between 15-18* and all in by 2500rpm with a total timing of about 35-38* this will require some screwing with the dizzy. those numbers should get you in the ball park.

then go to the carb.

1. set fuel pressure to 6lbs
2. adjust floats till fuel just barely dribble out the sight holes
3. set idle mixture to give you highest vacuum reading at idle
4. as idle increased back off the curb idle screw and redo step 3.
5. check vacume at vacume port on idle. cut # in half and that is size power valve you need in the front.

you should now be in the ball park. this set up should run good and only need light tweaking from then on.

or i could be full of **** but this is exactly what i did with my 383 and it took it from a disappointing heap to a tire melting monster.

I agree. A good carb choice and tuning,tuning tuning!!! I took my heavy 72 340 cuda from mid 14`s to low 13`s by upping my 650 to a 750DP and tuning it- jets, pumps, squirters and timing curve. Tuning and reading plugs is a lost art. You need to spend a day at the track and make ONE change at a time and see if it helps or hurts you ET and MPH. I also put on a set of drag radials in place of my regular T/A`s but didn`t really pick up much et, just made the launches more consistent. Your combo should be well into the 13`s with a low 2. to high 1.9`s 60' and over 100 mph even on street tires. I do lower the tire pressure to 15-18 pounds with both the drag and regular T/A`s, otherwise it`s straight off the street.