fastback383
Well-Known Member
I had wanted to take the old 400 back to the track 1 more time before I yanked it out and stuck the 383 in it for next summer.I had it to the track
once this summer and it went a best of 14.6. I thought it should do better than that, but being that the motor had at least 80,000 miles on it and I know it has very little compression and still the orig 975 casting heads there was little hope of achieving much out of it. But my son was bugging me to go to the dragstrip, so I figured what the heck, lets take it out 1 more time. I had gone to the trouble of advancing the cam 4 degrees a few weeks back with the intent of taking it out once more. So we loaded up the slicks and headed to the track. First pass, without unbolting the exhaust 14.4, heck a little better.Next pass, 14.38, not blistering, but at least in the right direction.So I go back to the pits, get the timing light out and set the timing at 35 degrees, it was at 32. It then cranks out a 14.08, now were talkin, close to the 13's , which is all I wanted. So next, I swap the orange ECU for a old skanky black factory one I had laying around. I had read on the board here that some of ou guys had trouble with them retarding in the higher rpm range. So I figures what the heck, next pass , 13.8 ! Almost 3/10's quicker with just that swap, go figure, who'd a thunk it. Thank you to whoever posted that about the orange boxes being junk!
Then it ran a string of 13.8's and one 13.77. I am sure with a few jetting changes and open exhaust 13.50's were within reach . But I was happy I had not blown it up, now I can yank it out and throw it under the bench for my next project, eithor a stroker or just a decent 400 rebuild .All of this from a absolutely whipped 400, I can not wait for the fresh 383 next year. fastback 383.
once this summer and it went a best of 14.6. I thought it should do better than that, but being that the motor had at least 80,000 miles on it and I know it has very little compression and still the orig 975 casting heads there was little hope of achieving much out of it. But my son was bugging me to go to the dragstrip, so I figured what the heck, lets take it out 1 more time. I had gone to the trouble of advancing the cam 4 degrees a few weeks back with the intent of taking it out once more. So we loaded up the slicks and headed to the track. First pass, without unbolting the exhaust 14.4, heck a little better.Next pass, 14.38, not blistering, but at least in the right direction.So I go back to the pits, get the timing light out and set the timing at 35 degrees, it was at 32. It then cranks out a 14.08, now were talkin, close to the 13's , which is all I wanted. So next, I swap the orange ECU for a old skanky black factory one I had laying around. I had read on the board here that some of ou guys had trouble with them retarding in the higher rpm range. So I figures what the heck, next pass , 13.8 ! Almost 3/10's quicker with just that swap, go figure, who'd a thunk it. Thank you to whoever posted that about the orange boxes being junk!
Then it ran a string of 13.8's and one 13.77. I am sure with a few jetting changes and open exhaust 13.50's were within reach . But I was happy I had not blown it up, now I can yank it out and throw it under the bench for my next project, eithor a stroker or just a decent 400 rebuild .All of this from a absolutely whipped 400, I can not wait for the fresh 383 next year. fastback 383.
