Do I need a valve job?

[Glennster]

My 1970 Challenger has 94,000 mile on her all original 318. It runs OK (not great), I get a good puff of blue smoke when I start her. The exhaust smells like I'm running rich or doing a real bad job of burning the fuel it's getting.
 Given the miles, the age and everything else, wouldn't it be real safe to assume this thing needs a vale job?

Next question, it looks like it's $500 - $600 for a valve job. Would I be better off to get a set of 340-360 heads totally reworked ($599) from Aero Head Racing out of Indianapolis Indiana?

AND, if I got that route, should I drop the extra $80 and get the Hard Seat valves for unleaded gas?

I appreciate any help I can get!
THANKS!

[67vertman]

Do a compression test first.  It well tell you alot about the condition of your motor.

See my thread on compression testing my 318. http://www.cuda-challenger.com/cc/index.php?topic=55839.0

[71chally416]

It's generally a bad practice doing a VJ on an old motor. It will likely smoke worse afterwards. Maybe some valve seals and a can of Restore until you can get another motor ready to bolt in would be a better plan.    

[Chryco Psycho]

I agree with doing a wet & dry compression test first , if the bottom end is weak changing the heads will nto help

[71chally416]

And I meant "old" as in a 1970 motor old. Modern motors go many more miles because the more precise fuel injection doesn't wash down the cylinders like the old carbs do wearing out the rings. The smoke on start up is the valve guides/seals leaking when you turn it off and it sits overnight. If you fix the guides then you have to do a VJ and it might or might not blow the rings out and make it smoke worse. I've seen it happen more than once. I fixed a 100K 360 Ford truck motor where I used to work that smoked on startup by just tanking the heads to clean them up and replacing the valve seals that were hardened and cracked. The guides were a bit worn, but not badly. It ran another 100K with just the new seals without the start-up smoke that used to choke everybody in the shop.  

[moper]

Like was said... when you have worn guides and iffy valve sealing on the seats, they are part in parcel with worn bores and rings. So the parts are evenly worn. When you decide to repair the heads, you will end up pulling more oil past the marginal rings and contaminating the chambers with it. You end up fouling plugs and smoking worse. I dont really like restore, but that's just me. If it's smoking on startup, it's probably valve seals, and just replacing them will help for a while. At least it gives you time to budget a rebuild or replacement. Also, make sure your tune is spot on. How is the carb and points? A tuneup by someone who knows the old stuff can do magic to an old engine.