Stupid question #428 (sorry 427 guys, had to enumerate)

[C4ME]

I can use fancy words but can not figure out for the life of me what size the manifold bolts are on my L98 motor! Plenum bolts too! I think they are metric (1.25 pitch I think), but am not sure as my tap set is just the popular stuff and this may be some obscure size.

To further thwart my bolt size problems, is there a reference one can purchase to look such things up? I have seen the "parts catalog" CDs on ebay and have been a little skeptical.

Thanks in advance,
Joe

 

[DMGroh]

Metrics are a pita. Take one of each bolt to Lowe's and they'll size'em for you. I actually bought one of each size metric bolt (some sizes come in 1.0, 1.25, and 1.50 threads/??) instead of just plain "fine" or "coarse" like SAE. I keep those metrics in their plastic bag and use them to determine correct size of whatever I remove from the car. Might even build one of those thread size gizmos that's in Lowes for myself.

 

[C4ME]

Metrics are a pita. Take one of each bolt to Lowe's and they'll size'em for you. I actually bought one of each size metric bolt (some sizes come in 1.0, 1.25, and 1.50 threads/??) instead of just plain "fine" or "coarse" like SAE. I keep those metrics in their plastic bag and use them to determine correct size of whatever I remove from the car. Might even build one of those thread size gizmos that's in Lowes for myself.

I have got a tap/die set of both metric and SAE. I alway run into trouble as there is little difference between certain metric thread pitch and SAE thread pitch. I am concerned as I am about to run a tap down the head thread holes and do not want to mess up:ugh. I really just need to know it they are metric and it sounds as though you are saying yes?

Thanks,
Joe

 

[DMGroh]

NO! I'm not saying anything about your particular situation....just that metrics are not as easy to eyeball as SAE. I would think that if you can't run a bolt down that thread with only your (ungreasy) fingers, it is probably not the right size/thread.