Don't Cross MeQ I've got a '70 Olds Cutlass S and bought these trans crossmember insulators from a company called OPGI. I didn't know where they go, as they don't seem to fit my crossmember. I sent them a letter to get an answer, but I was hoping you could help. Have you heard of these insulators, and where do you install them?Doug SmithVia e-mail
A OK, guys and gals, I know it's not a Chevy! All of the GM A-bodies are very cool, and we need to share the knowledge. The insulators you are referring to are used on the '67-72 Buick Skylark and GS models, and on the Pontiac Tempest and GTOs from '69 through '72. They slip onto the end of the crossmember and isolate the trans crossmember from the frame. These rubber insulators have brackets that bolt over them and encapsulate and retain the crossmember. This is to give you double rubber isolation from vibration. The Buicks were Businessman's Hot Rods, very smooth runners. The Olds and Chevys bolted their crossmembers directly to the framerails with 31/48-inch bolts. There may have been a few models in the Olds line that used the insulators, but all the Chevys bolted their crossmembers straight to the frame. Hope this helped. Good luck.
The Easy FixQ What is wrong with my combo? I have a '73 Chevy Nova with a 350 bored 0.040 inch over with flat-top pistons with four valve reliefs. It has stock heads (casting number 354434) with 2.02/1.60-inch valves, running 1.5 full roller rockers, a Summit cam (PN 1107) with 234/244 degrees duration at 0.050 inch lift and 0.488/0.510 inch max lift. I'm also using an Edelbrock Performer RPM intake, a Holley 750 double-pumper, a Holley Blue electric fuel pump, and a complete MSD ignition system. It has a TH350 transmission with a Hughes 2,500-stall converter and a stock 10-bolt rear diff with 4.10:1 gears and limited-slip carrier.
The car runs well and feels like it has good power, but does not have the power I think it should on take-off. It actually bogs when taking off from a dead stop and shows it's bogging at the track with 2.50 and 2.60 60-foot times. I believe the cam may be too big or the heads do not flow enough. This is a street/strip car, and I'd like to make the car run the best I can with what I have, less changing one or two parts. Could you please tell me what is wrong? I know you guys have the info and resources to tell me the biggest problem (or problems). Thank you in advance.Dave ParkerPhoenix, AZ
A Your package should have decent performance, but there are a few things killing the launch in your Nova.
You're right on track choosing the cam and heads as what could be hindering your performance. First, the cylinder heads you are using were originally used on 262/267 and 305-cid small-blocks from '75 through '80. They have a 60cc combustion chamber, which will give you good compression with your flat-top pistons. They should be helping the slow-speed torque with their relatively small inlet ports. However, you said that you have 2.02/1.60-inch valves. These head came with small 1.84/ 1.50-inch valves stock. If the heads were not machined correctly to blend the larger valves into the bowls of the ports, the larger valves could actually be hurting the performance. As I said earlier, the heads should help the torque, but would choke off the engine at higher engine speeds-right where your camshaft would love to run. So you've got an engine that acts like Dr. Jekyll and Mr. Hyde.
Now to get your car to move off the starting line, you're going to need more stall speed in your torque converter. The 234/244-duration camshaft is killing the torque output of your engine below 3,000 rpm. Even though you have 4.10:1 gears, the 2,500 stall isn't letting the engine get into its powerband, and the engine bogs when you stand on the gas. Check with Hughes Performance and pick up a 10-inch converter. This will stall around 3,400-3,600 rpm, depending on the amount of torque your engine will produce in this range. This will make your car launch well, but you're still going to run out of air with your cylinder heads.