I have a 92 Camaro RS TBI 305 (Manual) with T-tops. The car has sat for the past 2 years while I was out of the country, but have since got the car running. I've changed the oil and filter, O2 sensor, fuel filter, air filter, replaced the radiator fluid, drivers side valve cover gasket (looking for an oil leak), and started replacing some cracked and worn hoses. I still have some problems and would like any advice on what to look for or whether to use stock or aftermarket parts.
1) I've still got a small oil leak that I don't know where it is coming from, so my plan is to change the passenger side valve cover gasket and go from there. 2) I have a passenger side exhaust manifold leak, and would like an opinion on whether to use a direct replacement or get headers. If headers what is a reasonably priced set that is relatively easy to install (I'm a college student with little funds and little time). 3) When I am going 70 in fifth gear and go to accelerate the car shakes and struggles to accelerate. It also shakes when I get it up to higher speeds.
Also would a set of subframe connectors be a priority buy especiall since it has T-tops? Any suggestions about parts, problems, upgrades, etc... are welcome.

 

Oil Leak. Clean the engine as well as you can. Drive for an hour, and then look to see where the fresh oil is coming from.

Going with a stock replacement on the exhaust manifold would be the cheapest route, but, if you have to be in there anyway, it is a golden opportunity to install headers. Take a browse thru the exhaust boards for good recommendations on headers, and what you can expect in the way of pricing. You can spend anywhere from 100 bucks for plain jane painted headers, to 600 bucks for stainless steel ceramic coated......

Depending on the headers you get, there will probably be other exhaust modifications required to hook 'em up.