Performance questions - HELP....

[Snak Iyz]

Thanks in advance for anyone that can offer insight into my following description. Also, I am professed novice and mechanically challenged when it comes to this stuff, so please don't be afraid to provide as much detail as possible or let me know if you need additional information.

Under the hood: Stroked 351W to 392. Carb is Holley 80870 double pumper, downjetted to 70 primary/ 72 secondary. There was no timing pointer installed, so I think this may be the or one of the problems in getting everything dialed in. My shop is working to get a pointer installed and diagnose from there. Initially was set for 18 degrees up to 38 degrees. Without the pointer though, these could have been wrong.

Problem: Upon easy acceleration everything is fine. With more heavy and even aggressive acceleration there is a 'slight pause' at the beginning of every gear. It grabs then pauses and then grabs again and does fine from there. In addition to the initial pause, under steady acceleration, cruising in 3rd or 4th gear, there seem to be slight spurts. These are not big jolts, but just little 'hiccups' you can feel through your gas pedal foot. It is not smooth.

My new shop is telling me they think the carb is too big for the engine, but they do not seem completely sure. My builder down in San Diego says he puts 870's on these kind of engines all the time. Definitely need your input on this area.

I feel like I am not getting near the horsepower and pull I should be getting, although I have not had it dynoed yet. Suffice it to say, it seems difficult to try and break the rear tires loose with acceleration as opposed to a high RPM rev and letting the clutch out.

Hope this offers enough info to gain your opinions. Thanks again for any help. Feel free to contact me via cell, if it is easier than typing out an answer - 949.466.9746.