Several years ago swapped the Holley 2bbl for a Holley 4160 and now I have to replace the Hooker Longtube headers. I am considering going back to the stock exhaust manifolds? The truck has a mild cam so I do not exceed 3k rpm, nor have I even gotten the 4160 into the secondary jets. I would appreciate comments, or suggestions whether using the original exhaust with the 4bbl set up would be a poor application

The 65, with a 68 289/302; although it has been some time, I do recall the stock set up had a great deal of 'get up and go'.

 

If you aren't running over 3000, just put some 302 manifolds on it. Those motors don't do much below 3000.....you should try regearing so you can run it from 3500 to 6000 all the time, you'll really enjoy it!