ASK RAY

GM GUY GOES BLUE OVAL!

Q: Ray, I find myself in strange territory, as in my past life I had been a GM guy, yet I recently bought a 1971 Mercury Comet in stock form. I have had much fun updating the differential and performing a disc brake conversion in front. While retaining the stock 250-cu.in. inline-six engine, I did mount a Tremec T-5 five-speed manual behind it.

Now I’m trying to improve the performance under the hood, so I replaced the stock distributor with an aftermarket HEI distributor, due to vacuum advance problems. I installed HEI-style plug wires and Autolite #46 spark plugs gapped at .035 inch, and I had the carburetor completely rebuilt by an old-school specialist, installed a new stock fuel pump, and added an inline filter.

Now it starts like a new car; however, while accelerating, it will cough, then it will sputter. I have timed the distributor by ear, advancing to achieve the best performance and starting.

What spark plug would you recommend with the HEI, and what would you gap them at? I tried