[Snowman]

I have a 67, with a 383, 4spd Muncie and 4.11 read end.
I have only had the car a year. I have noticed in the past that when cursing in 4th gear, if I give it more gad than just easing into it, I would hear this violent metal clanging together sound from maybe the bell housing area. Then, I noticed today that when driving a a much slower speed and very low rpm’s I went to give it a bit of gas and I heard the same but, obviously just not quite as violent.
It doesn’t feel like the transmission is slipping but, I could be wrong. Any thoughts?

 

[Stroker Ace Ventura]

Sounds like detonation, not transmission. You check your timing lately? Change gas brands or octane? Old gas?

 

[Snowman]

Good idea. No, I haven’t checked the timing since I bought the car a year ago. Will try that.
Same gas, good quality.
Thanks for the idea!

 

[kimmer71]

Throw it on jack stands and check for play in universal joints and rear gears? Also check engine and transmission mount plus shackle bushings. It sounds like something is trying to clime out of a spot where it belongs securely.

 

[Carl Stevenson]

By chance is it your starter drive hitting the gear on the flywheel? I've heard an awful noise, under acceleration, when the solenoid spring breaks and the starter drive is floating back and forth on the armature shaft. I know it sounds silly, but check it...

Have you done any work on the car recently that might have changed something?