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Anything that bolts directly to an L98 cylinder head or engine block you should find being 3/8-16 and various lengths, there will also be a mix of bolts and studs.
Actual brackets and accessories can and will be a mix of Metric and USS. You have nothing or just a 'bucket of bolts'?
Anything that bolts directly to an L98 cylinder head or engine block you should find being 3/8-16 and various lengths, there will also be a mix of bolts and studs.
Actual brackets and accessories can and will be a mix of Metric and USS. You have nothing or just a 'bucket of bolts'?
I have a few bolts. I was told that as long as you stay around 1/2 inch of the bolt in the block you are OK. Using a screw driver to check depth and old bolts to check size and pitch.
Is the engine and drive train SAE and the Body Suspension Metric?
Last edited by Richard Ames; Apr 17, 2018 at 03:15 PM.
I have a few bolts. I was told that as long as you stay around 1/2 inch of the bolt in the block you are OK. Using a screw driver to check depth and old bolts to check size and pitch.
Is the engine and drive train SAE and the Body Suspension Metric?
An L98 water pump mounting bolt is spec'd @ 1 3/4 long so measure thickness of the flange and subtract from the 1 3/4, that should give you a general dimension of thread required for install. Confirming depth will keep you from 'bottoming'. I might use something other than a screwdriver to do depth and measurements, even the least expensive digital Verniers usually have a depth indicator.
It will change for the Metric hardware in the accessory bracketry. Generally speaking you want flange head hardware for the hardware.
NO to your generalities regarding SAE - Metric. The alternator hardware is M10x1.5 and M8x1.25. There's other mixes involved. To confirm threads I'd buy an M6x1.0, an M8x1.25 and an M10x1.5 to confirm all other than 3/8-16.
Compressor bracket to engine is 3/8-16 but the compressor to the bracket is M8x1.25 I believe. Force nothing - confirm and use thread chasers.
If the OP can get a copy of the "y-body parts and illustration catalog," hard copy or .pdf, most bolt/screw/nut part numbers, as well as sizes, are called out in detail. hopefully, this should get you started....
I was looking at your reply about bolt sizes, and there is a bracket #9.171 that shows it mounts on studs. Do you know the length of the
upper and lower ones that nut #4 attaches to. This was on page 10-91 of GM service parts operations manual.
I was looking at your reply about bolt sizes, and there is a bracket #9.171 that shows it mounts on studs. Do you know the length of the
upper and lower ones that nut #4 attaches to. This was on page 10-91 of GM service parts operations manual.
Year seems to matter along with bracketry. If the later 'denso brackets are used then hardware would change. I
3/8-16x2.73/3/8-16x1.32 and another that's spec'd @ 3/8-16 (both ends) 2.5 LG
GM continued this with the LT1. I just did the intake manifold gaskets on my 92. The EGR valve (I think that's what it is) on the driver's side rear of the manifold is 3/8s heads. The similar valve on the passenger side rear of the manifold is a 10mm. Why is there a mix of standard and metric on the same part?
1988 Engine accessory bolt sizes?
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