91 low to mid stutter.

[givsum]

I recently purchased a '91 383 stroker. This car is near flawless with only 37k miles. All work was done buy a top performance shop in Vermont. Since purchasing it, I have had it to several mechanics, just to check it out thoroughly.

Now, I'm left with 1 unsolvable problem. On occasion, "not always", I will get a low to mid range miss/hickup. Kinda feels like a fuel filter. Unfortunately both mechanics who have looked at it and test driven it have not noticed anything.

I have dyno sheets showing 412hp@4200. So, I expect a lot more pull than I'm getting. Just seems a little groggy at times and as I said has a tendancy to hickup once and a while. Does seem to gradually be getting worse. I need help unleasing the power I know this vette has. Any advice or thaughts would be appreciated.

 

[vader86]

Are the dyno curves smooth and flat, or really choppy or peaky.

It should be a fairly smooth line until you get to high rpms, where the HEI falls off.

Could you scan and post the dyno sheets?

 

[givsum]

Took a while, but here is some info.

 

[givsum]

My scanned files are too big. Can I e-mail them to you?

 

[8388]

What's your fuel pressure doing when the symptoms are present.
Get a fuel gage with a long enough hose and tape it to the winshield while driving. Also what do the spark plugs look like, especially right after wot run ?

 

[givsum]

Had the fuel pressure checked. All was fine. Very hard to check plugs. Headers are in the way. Leaving it with my mechanic for a few days. Hopefully he can find the problem. I'm going to have him replace the plugs. Hopefully that is the problem.

Which plugs should I be using?