Try a larger squirter, 31's or larger to help w/the stumble. You still might have a vacuum leak somewhere.Have the engine idle & spray starting fluid at the carb base gasket & intake to cyl head gasket & all around the carb for other possible leaks,( it's very flamable so be very careful & done you it on a really hot exhast manifold, try the starting fluid spray when the engine is cold, just to be a bit safer. With the engine idleing ,if the engine RPM goes higher when you spray starter fluid @ the areas mentioned, that means there is a vacuum leak where you are spraying the starter fluid.
What did you end up doing s far as your fuel system? Going w/a fuel cell & stock gas tank?
Increasing the feed line from the gast tank to the front?
IMO, it is really a big waste of time to run cheap 87 octane fuel in your stock tank & run a completely different fuel cell & lines just to run 91 octane.
You will get better results & higher octane & be able to run more boost when running the 87 octane & injecting methanol.(I think I already stated something simular before?)
If you have a LOWES or Home Depot near you, they should sell Xylene so you can pick it up locally. FORMULA 2 Xylene R+M/2...117 Cost...$2.75/gal Mixtures with 92 Octane Premium 10%...94.5 Octane 20%...97.0 Octane 30%...99.5 Octane Notes: Similar to Toulene. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Usually mixed with Toulene and advertised as *race formula*.
