Check the timing at 4000 rpm with the vacuum advance disconnected. If your timing goes over 36 degrees adjust it. Too much timing can be as bad as not enough. I would then test the springs - My bet is they are weak and need to be replaced to get 5500 out of them. If you are as competetive as you are by shifting at 5000 then stick with it. If you have a cam that is made to make HP up to 5000rpm then you can typically take it to 5500 (with good springs) before shifting without losing any time. If you are running a stock cam then you need more cam and better springs before you run it up to 5500.
this engine isnt bone stock is it? thats a good time! espically for a stock motor that isnt running as good as it could be
I bet it's ignition related. Maybe where the timing is set, or maybe it's not holding on to where you set it consistently. Mine did this and it was some combination of a slop in the distributor gear/shaft, bad stock wiring, and a funky coil. I can't tell you which one solved it as I replaced the whole ignition system at once, but it sure did what you're describing. You don't suppose that new distributor gear is chewing on the cam gear or vice-versa, do you?
Well so many people can't be wrong! It's one of the three issues listed here... more then likelly. Ok, lets get the ride fixed and see what she will really do Good luck. Terry
I had the same problem but at 7500. my problem was my distributer and ignition system. git rid of the HEI and got an msd ignition coil and distributer and it goes to 9000 without a problem BUT my motor is set up to run at that RPM
Found the problem, SEVERE valve float. I changed the ignition system to a complete MSD system ( dist, coil,wires, 6 al ) and the fuel filters before finding the problem. The valve springs only had 65# at thier installed height. The valve float was so bad it trashed the 351 heads and the valves. Just got the new DART heads and LUNATTI bracket master cam. The mav will go back together and we shall see what she will run then. Thanks for all the advise, you guys got it right
Glad you got it figured. Too bad you spent so much dough finding it. However, the best excuse to buy goodies is when you are on a mission! I get all my best tools and parts that way. Congrats on the MSD system. You didn't really need it to fix your problem, but it sure will be nice having it! I gotta remember your method of getting Dart heads! I believe I'll give it a try... "Honey, my valves have been floating. The only way to fix it is to get some AFRs."
