So what is the simplest way of blanking off the inlets on the manifolds? just a bolt in each hole?
I've heard of people crimping the tubes but would rather bolt the but do not know the size.

 

I just cut them as close as I could and spot welded them but I have headers so not sure if its different for stock

 

I'd always assumed they were a pipe plug thread..1/4 NPT?

But been years since I looked.

 

You mean decades....

I don't know if they came stock like this or not, but back when AIR was introduced in the mid-1960's I used to see some medium duty trucks without the AIR system and the AIR injection holes in the manifolds were capped with brass pipe plugs.

 

Thanks

 

1/4,pipe plugs available at Hardware stores.

The bitches are hard to get out since they are usually rusted in solid. I puled the manifold off the car, cut the tubes off flush to the nut, WD 40 the p*** out of it, and used an impact wrench.

 

PB Blaster is FAR superior to WD-40.

Whats really funny is, the BEST penetrating lubricant/rust dissolver is a 50/50 mix of acetone, and auto trans fluid. Both of which are cheaply available in the auto section at wal-mart....