84'22r

I'm planning on putting a 20r head on my early 84' 22r block. I had a few questions about it.....

I live in california, if i'm still using the egr system (just installed a new valve) will i still have problems passing smog? Will the egr system take care of emmisions?

Also, what can i keep from my 22r when i swap the head? Cam? Rocker assembly? Will i need to degree the cam a bit once i get the head on? I read somewhere that the swap can throw off the cam a bit..

84sr5yoty

If the engine is in good proper tune the answer is no. However, using the 20R head bumps up the compression, which also bumps up NOX. Make damn sure that the EGR system is working properly (EGR valve, modulator, BVSV, vacuum hoses, ect.) and that ALL passages from the exhaust manifold, to the head, to the carb are pristinely clean.

Cam, rocker arms, and rocker shafts can be swapped as they're all the same from 75-95. It's best to purchase new rocker arms if you get a new cam. The cam lobes and rocker arms develop their own particular wear pattern to eachother. You might as well replace the rocker arm shafts then.

You don't have to, but it's always a good idea to degree a cam since most aftermarket camshaft/crankshaft gears aren't very accurate these days. I've had them off as much as 14 degrees retarded on old American V8 engines. Also, if you have the block or head shaved, you will need to advance the cam 1 degree for every .010 removed from either (head or block) with an adjustable cam gear.

84'22r

thanks a bunch, this is what i had hoped/thought. Yea i replaced the egr valve and cleaned out the vacuum modulator with some carb cleaner and just had it pass smog a week ago. The motor has about 123,000 miles so it is in pretty good shape.