I've had a beautiful 69 skylark convertible for some 36 years now (guess that makes me the original owner!). About 6 years ago, I put in hooker headers and dual stainless exhaust w/Flowmasters. It ran lean, so I got a jet kit and swapped the #68 (I think) main jet to a #72. She runs better but I still think I'm missing some power. Should I have also changed the rods? I have cleaned and rebuilt the carb myself a few times over the years so I don't mind taking it off and doing it correctly again. Anyone know the proper jetting setup (after exhaust upgrade) or link to a company in the know? It has the stock 4 bbl Rochester and air cleaner with no other mods except the exhaust. Auto transmission (unfortunately). Any advice would be greatly appreciated. It also is a bear to start in the winter and after not running for a few days..... Thanks, Jim
Kind of off the subject but I have a 69 convertable too. I am thinking of hooker headers and a performer intake. I would be interseted in how this turns out as I don't have much expierience in carb set up. The headers don't make it to loud do they? I have a 455 in mine. Thanks
headers The set up I got was recommended by a performance shop when I told them I wanted more power without obnoxious noise. I would recommend the exact same setup for you if you want similar. Hooker headers (I got steel but would recommend the extra $$ for ceramic since recently I see some slight corrosion), dual STAINLESS exhaust and Flowmasters. All together with install it was about $1300 but one of my employees knew the owner and that was 1998. I never upgraded the manifold as a slight increase in horsepower was not worth further changing my perfectly stock, original owner car (actually my dad bought it new in 69, but I've got the same name!). I have found a few sources/companies in the past years with great recommendations on how to smartly jet out my dirt bikes, I would think there are aftermarket carb companies with the same but I have searched far and wide. Check any replies to this string and you will also be enlightened... Good luck, Jim
P.S. I've got the stock 350 in her still, would love to swap it for a big block with manual trans but that would half its value......
Back to the issue at hand... With a .004 increase in jet size, yes, I would strongly recommend going up one size in rods. Have you done any distributor work? Lots of performance to be gained by re-curving the dist.
Something to remember here is the idle and off-idle metering. Rejetting the carb will help the heavy throttle performance, but will not help the light throttle response. That will require opening up the fixed metering for this. Also, the secondary metering will require either a different hanger, or different rods, to enrich the metering there as well. The jets are only part of the puzzle. Ray
Ray, Thanks for the info. It's been 6 years since I bought the jet kit, any ideas on a company that's smart enough to sell me a correct, complete upgrade kit with correct rods and jets, etc for my Q-jet? Thanks in advance, Jim
Any advice you get here will be as good as (if not better than!) "professional" advice. There is no "formula" or "standard" for tuning a carb. The best way to get it right would be to put the car on a chassis dyno with a wide band O2 sensor and have an assortment of jets, rods, etc. on hand. Short of that kind of investment, your best bet is to get some advice here, make some changes, see how you like it, repeat!
