Sock MonkeyQ I have a '77 Chevy Stepside K10 truck with dual tanks and I've been having a fuel delivery issue. I replaced all the visible filters and pump, as well as the power valve in my Holley. I'm still having problems with it not idling, and it sputters under throttle. Did the '77 come with an in-tank filter? I did not start having problems until I was four-wheeling and slid sideways; ever since I've had problems at low speeds. Freeway driving is still OK, but I go through a lot of fuel, more than usual. Mike HughesVia e-mail
A To answer your question, yes, there are filter socks attached to the end of the pick-up tube in your tanks. However, I don't think this is your problem. You say this is an idle and stumble problem and the engine runs fine on the freeway. There is a much higher fuel flow demand on the fuel system during freeway driving.
You also said you have replaced the power valve in your Holley carb. Was this because of an overly rich condition? Now, the carb may be maladjusted if the previous owner had it set to a poor-condition power valve. Or you may just need a full carb rebuild. The idle air bleeds in the main body of the carb are rather small and can pick up trash. If the idle or main air bleeds are plugged or restricted it will cause the carb to run rich. This may help explain your fuel consumption problems. Either pick up a Holley Strip Kit for your model carb or send your carb off to Sean Murphy at SMI. Sean is a Q-jet specialist, but he has many years tweaking Holleys. You can reach Sean at 714.842.1881 or online at smicarburetor.com
Not Worth The DrillQ I am rollerizing a small-block 400, complete with Vortec heads, just like your recent buildup. I have a perfectly good Edelbrock Performer sitting on the mill in my '76 Vette. I have heard of guys machining the bolt holes to use regular intakes on the Vortecs. Do you have an opinion on this? If I port-match them, is this a viable low-buck solution? Or am I asking for hassles and performance loss? Thanks.Gary LacoursiereWinnipeg, MB, Canada
A Why do you think we put this book out every month? It's just so guys and gals like you can steal our ideas. Hopefully, we come up with pertinent information to feed your performance habit. Yes, used Performer manifolds are a dime a dozen out there. However, the unique vertical bolt pattern of the Vortec cylinder heads, with their plastic reinforced silicon intake gaskets, seal up very nicely. Sure, some people out in the field and aftermarket parts suppliers have redrilled the Vortec heads to take the standard Gen I small-block manifolds. What I don't trust is bolt holes that are adjacent the coolant passages in the heads. When you drill the original early bolt pattern, you somewhat cut into the standard Vortec pattern, and there is very little sealing surface around the coolant passages. I think it would be money well spent for the proper Vortec Performer and a long way toward peace of mind that the coolant is going to stay in the cooling system, not in the oil pan! Pick up a Vortec Performer from Edelbrock under PN 2116. For more information contact Edelbrock at 800.416.8628, or online at edelbrock.com
Timing's EverythingQ I have a '64 Chevelle with a 327 and a four-speed. I just rebuilt the 327 with 0.030-over flat-tops and a polished and balanced steel crank. The top end is a set of 462 heads with 1.94/1.60-inch valves with a bowl blend. I used a complete Comp Cams XE268 kit and an Edelbrock RPM intake with a 1406 Edelbrock Performer carb. The ignition is a MSD Pro Billet HEI. I am trying to set the timing, but I'm having problems. I have the timing at about 18 degrees BTDC. It doesn't seem to have a lot of acceleration. The compression ratio is 9.5:1. The car does not have headers, but it does have 211/42-inch dual exhaust. The Flowmasters sound like glasspacks at about 2,600 rpm. Would an X-pipe help the sound above 2,600 rpm? The car also has 3.08:1 gears, with a M21 trans. I am not sure how far to go with the timing. Thanks.Ryan BlevinsYakima, WA