my car ran perfect until I had the tranny rebuilt all that I changed was I had the reverse manual valve body replaced with an automatic and the high speed converter, but it had a 2 inch spacer a 5/16 inch of gaskets removed now it misses terribly mostly at 2,500 range any suggestions? I have an excellent mechanic who has gone over everything, tomorrow were gonna put the spacer back on and see what happens I also have an extra carb were gonna try if the spacer don't work

 

SM -

Kinda sounds like you crossed a couple of plug wires.

However, a 2" CARB spacer will change the characteristics of the engine.

Since you went from a manual VB to an auto VB, you did install a kick down linkage, right?

Archer

 

tx for your input he checked all the wiring in fact he put all new plug wires on checked the timing on each individual wire with the timing light

 

and the kickdown linkage is installed right I used the one from broughlins im thinking it has something to do with the spacer the car just doesn't have close to the power it had before I took it off

 

sm -

Couple of things:
You didn't mention the engine or tranny
Are you sure you're not starving for fuel as the RPMs go up. (Inadvertent kinking of a fuel line.)
When you checked the induction on each wire did you check it at idle or at 2500 RPM, where the problem starts?

Archer

 

its a 383, automatic and it was checked at the high rpms it runs fine after getting into the high rpms my mechanic thinks when he took off the spacer the thickness of the bracket would cause the bolt to go in further and maybe damaged a pushrod? the car was raced was running in the 11's and has a monster cam and it might need that spacer were gonna put it back on and see what gives I took it off in order to put a stock hood back on it

 

SM -

You can't use the same carb bolts with a 2" spacer as without, and the carb bolts are nowhere near the push rods.

A bad push rod shouldn't cause a miss fire and you should hear it an any RPM.

The spacers work two ways.

A single bore spacer will increase plenum size and help your top end speeds. It can be a + or a - at the low end.

A four hole spacer should increase low end torque and may or may not affect the high end. They can help a slightly over carbed engine with a mild hesitation.

Neither should cause a 2500 RPM miss.

Still sounds like a flat spot in the carb or some kind of ignition problem. For the carb it might be a clog in one of the transition circuits and may just need to be blown out.

BTW -
If you haven't already, posting full specs may help. Despite what some people do, a real 11 second "vintage" car has no business on the street. That might also be part of the problem.
A car designed for a 3500+ RPM launch may not be happy in the 2000 RPM range. Might be why he had the manual VB.

Archer

 

sorry I didn't mean the carb bolts I meant the bolt holding the bracket on but I called the previous owner and just found out that bolt can't go far enough in to damage the push rod it will dead end he thinks it might be getting vacumn at the gasket I gonna spray starting fluid around the gasket at an idle and see it picks up before replacing the spacer

 

 

put the spacer back on and checks for vacumn leaks and it didn't make much difference it did idle smoother though anyhow the kickdown linkage won't work with the spacer so we took it off put a new gasket on it and it ended up being the timing, it was set at 13 but runs best a tdc I still have a miss but its not bad he also cleaned the carb but I don't think that was the problem the timing seemed to be more the problem