[jim_howard_pdx]

Peckerwood has you on the right road.

REBUILD THE CARB
Get a Barry Grant rebuild kit.
Get a Can of Carb Cleaner.
Dissassemble the carb and soak everything at least overnight.
Wash the soaked parts in HOT water, then wash them a second time, then wash them a third time.
Blow out every circuit with carb cleaner and then with compressed air.
Replace the power control valve(s)

Since you have cammed UP, you are going to be WAY LEAN. This is disastrous for an engine. You probably need to jet up 2 to 3 jet sizes if you had a GT based car and 4-6 jet sizes if you had a grocery getter.

Holley stamps each jet with a number that is simply a reference tool. The number by itself has NO REAL MEANING. But if you have 70's for instance. you might try 73 or 74 jets as a baseline. Then jet up or down by two size increments.

As you do your rebuild, use a backfire control valve which costs about 8.00 from spectre. This will prevent future PCV blowouts. This is a must on any holley.

I like to plug read a car. At proper jetting the plug with be light gray or light tan depending on what the fuel company adds to make the octane number of the gasoline you burn. If you are way lean, it will be gray, so do not accept gray as a finish line. You must jet up until it goes sooty. Then you know you are rich. Now back down to where the soot goes away and you have mostly tan or gray.

If you have a metering plate instead of a metering block in the secondaries, you should buy the holley kit to convert to the metering block. Now you will be able to jet the secondaries.

If you have a secondary power control valve I like to use the holley plug to close that down, then jet up 3-4 sizes from the primary venturis.

This may take you a week or more to nail down the proper jets. You need to buy a timing light and learn to set the advance. If you have a vacume advance you may want to block it off at both the carb side and the vacume can. Vacume advance is for stock cams with stock driving in mind. On a performance engine it will make you detonate at highway speeds which will ruin your valves, valve guides and piston rings.

A cam like yours should never see more than 32 degrees of total timing with pump gas, and no more than 36 degrees with racing gas. A vacume advance is putting you into the 40-45 degree area which is not appropriate for a performance cam.

Remember that clean air is essential to holley performance. Buy K&N rechargeable filters. They are medical grade cotton elements with a light coating of oil to trap the small dirt that clogs up a holley. I use a X stream unit that adds top air filtration to the side filtration and really like it alot.

That cam is a little big for a stock lower end. Keep the RPM below 6,000 or those cast pistons will come back to haunt you.

Consider buying some World Product Victor Jr heads. This will give you an additional 30-40 hp and alot better fuel burn.

Hope this helps.