GM TPS mounting screws
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
GM TPS mounting screws
As some of you may know, I am in the middle of dumping the MEFI 3 and upgrading to an Accel Gen VII on my 70 RamJet 502 My problem is this;
I purchased a Holley dual 58 mm throttle body which needs the lever controlled TPS like those used on a 92 Camaro or Firebird and probably Corvette also. The old RamJet TB used a shaft controlled TPS which had shorter 3/4" mounting screws. I need 1" long screws for the lever TB. I can't determine the size machine screws that are needed to mount the TPS. They are not english (i.e 8-32 or 10-32) and don't appear to be standard size metric (i.e 4 x.7 or 5 x.8). The only thread gauge that appears to measure is a metric 0.75. The major screw diameter measures .176. Any idea wtf they are??
Bullshark
I purchased a Holley dual 58 mm throttle body which needs the lever controlled TPS like those used on a 92 Camaro or Firebird and probably Corvette also. The old RamJet TB used a shaft controlled TPS which had shorter 3/4" mounting screws. I need 1" long screws for the lever TB. I can't determine the size machine screws that are needed to mount the TPS. They are not english (i.e 8-32 or 10-32) and don't appear to be standard size metric (i.e 4 x.7 or 5 x.8). The only thread gauge that appears to measure is a metric 0.75. The major screw diameter measures .176. Any idea wtf they are??
Bullshark
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
You might try a search, but it's been awhile. If I remember correctly, they're a 4.5 metric thread and someone dug around Home Depot for a couple of hours one day and actually found a couple that worked. Otherwise, I'd contact Street and Performance www.hotrodlane.cc and search their catalog for TPI parts or just call them.
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Looks like it is probably a non-standard metric machine screw M4.5 x .75 (course thread). I haven't found any source on the internet, but now that I think I know the size, I will do some calling around the local fastener houses.
The bone yard is certainly an option if they will sell screws only. Replacement TPS's at the Zone come with the screws but I already have the TPS. I called GM, but they want to sell me a fastener kit for $29. What's that old saying...... I want to meet the bone head engineer that is responsable for this
If it wasn't a brand new Holley throttle body, I would just drill and re-tap for a standard size.....might still do that.
Bullshark
The bone yard is certainly an option if they will sell screws only. Replacement TPS's at the Zone come with the screws but I already have the TPS. I called GM, but they want to sell me a fastener kit for $29. What's that old saying...... I want to meet the bone head engineer that is responsable for this
If it wasn't a brand new Holley throttle body, I would just drill and re-tap for a standard size.....might still do that.Bullshark
Last edited by Bullshark; Feb 25, 2007 at 09:11 AM.
