225 Buick

[Chris J.]

I have a stock 225 Buick in my 68. I plan to install a four barrel carb and intake, but I don't know the difference between odd-fire and even-fire. Could someone explain?

[Tim]

Has to do with when the cylinders fire in relation to crankshaft rotation. Odd-fire's fire at different increments, even-fire's fire at equal increments of rotation. All 225's are odd-fire. '75-early '77 231's are odd-fire, late '77's and on are evenfire's. If you're looking for a four barrel intake for the 225, I'd suggest the Offenhaeuser Dual Port #6035-DP and gasket #5996. This intake is designed for low-mid range power increases which is where Jeeps operate the most. The other intakes on the market are designed for high-end and offers no improvement below 3500 rpm. A Holley 390 cfm or Carter 500 cfm carb is a good choice if you don't go with a Q-jet, which is the best carb for off-road.