Your best bet is to call up a dealership in your area and ask a a service writer. I believe in your area, the best Chevrolet dealer to go to.....damn, I can't think of the name of it now....it starts with a "W" and they usually hold a Corvette show every year at their dealership...usually in May or June. LemonPeel might be able to help you here. She's a member of our Forums and she and her husband are very active in New England Corvette events.
Walter Earl Chevrolet in Bridgewater MA is the dealer that your thinking of. He has the Corvette Show at the dealership in May of every year. I bought my ZR-1 from Walter Earl and don't have any complaints on service etc.
Also DeSantis Chevrolet right in Brockton MA, who is the Sponsor for the South Shore Corvette Club that LemonPeel and myself belong to, services a lot of Corvettes
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
$$$$ & sence
I would say if you pay over $180.00 your not getting a deal.
the 84 EGR is a piece of cake to get to ( unlike 85 on up )
Check carparts.com for the rough price for the part. It's just 1 vac line and 2 bolts bada bing it's out, clean the area, slap the new gasket down, tighten it down ( replace the vac line ) and bada-boom your back on the road. ( How do you know you need a new EGR?