I recently ordered the proform billet base plate (throttle plate) for a 3310 (4600 series) carb. It is supposed to have a way to adjust the secondary butterflies without taking the carb off the manifold (adjust from the top) but I am looking at the base plate and don't see any adjustments what so ever. Can someone tell me or better yet post a pic of what I'm looking for. I dont even so a small screw hole likethe orginal baseplate has on the underside. Also I'm installing the quick jet change setup. I see that some people use jet extensions to keep the jets submerged under hard accelleration. I'm assuming these are only used on the secondary side? Also I know the stock front metering block is 72, what would be the jet size for the secondary side if I had the stock metering plate, 76? Allen
It's been awhile, but I'll try and remember. Look on the passenger side of the rear throttle shaft. One the end of the shaft is a bracket that turns with the shaft. There is a finger on that bracket that bends back over the base plate. There is a set screw that adjusts where that finger stops, which controls how far the rear throttle blades close. On a factory carb, you turn the set screw from the bottom. I believe ProForm put the set screw slot on TOP of the base plate. Move that finger out of the way and you will see the set screw. Also, jet extensions only go in the back. If you have power valves front and rear, start with square jetting (72/72). If your car leaves hard, take out the rear power valve and up the rear jets about 6 numbers. Have fun.
thanks for a quick reply, havent had a chance to look since I posted but will check it out tonight after work. allen
Hmm interesting, I just looked at my baseplate and there is no screw. That was the first place I looked too, right where you told me to look since I know thats where it is with the holley baseplate. Now I'm wondering if I should send it back and ask for another. It is the correct one I ordered has the number 172 on the butterflies. Anyone have a pic the can post? Allen
Do you mean there's nothing there, top or bottom of the baseplate? What stops the secondaries from closing all the way? Could be interesting.
I just went to proforms web site and saw the pic of the base plate with screw for the secondaries. My baseplate does not have this so I'm on the phone, waiting for a rep from summit. I want to exchange it for one that has the adjustment screw. I dont know why this one doesnt, right part number just incomplete. to answer your question on the 2ndary side, the piece at the end of the butterfly shaft looks like the stock piece and just come to rest on the baseplate. Allen Allen
so the guy from jegs is telling me thats a separate add on piece, not included with baseplate? he had the upgrade so i did order it Part #: 67237. does this sound correct, can some one chime in, did you buy separately or was it already on the baseplate. $16 so no big deal, just want to know though. Allen
