drainage hole info - ZR-1 Net Registry Forums

zpyroro · 08-11-2022

Anyone know where I can access the info on how to open up the drainage hole under my he plenum? There was a GM service bulletin years ago about this. Thanks

Young1 · 08-11-2022

There is a bulletin to drill a 3/8 hole in the rear of the block in The Valley of the plenum. Why not use a drill bit, a stiff wire and an air blower to clear the oem tube? You have to pull the starter to do either anyway.

08-11-2022	#1
zpyroro Join Date: Aug 2022 Location: california Posts: 3	drainage hole info Anyone know where I can access the info on how to open up the drainage hole under my he plenum? There was a GM service bulletin years ago about this. Thanks

08-11-2022	#2
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 880	Re: drainage hole info There is a bulletin to drill a 3/8 hole in the rear of the block in The Valley of the plenum. Why not use a drill bit, a stiff wire and an air blower to clear the oem tube? You have to pull the starter to do either anyway. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.