I need to block off the smog fittings on the

header that i just bought. they are threaded

but i do not know the thread size - does anybody

know the thread size? Or is there another way to

block them off.

- Jeff

If they are the same size as the fittings in the stock manifolds, if I remember right they should be either 1/4 or 3/8 NPT pipe thread....

2Manyz's - one is just smaller than 1/2" npt and the other is

slightly larger than 1/2" npt. so i wonder if it is a straight

thread.

- Jeff

Once you find the correct size make sure to use plumbing plugs.Plumbing threads are done in a tapered v .Therefore as the diameter increases it seals the hole.A standard bolt or electricial plug is not tapered and you will get a leak around the threads. Daniel

I found out that both of the taped holes are straight

threads- One is M20x1.5 and the other is M22x1.5

Those are fine thread metrics. I went to a local fastener(sp)

place and got one of each and a crush washer for each.

( crush washers are also found on a spark plug )

I've cranked them tight but will not be starting the car untill

the middle of next month - I'll let you know how it works.

- Jeff