I changed the turbo and i cant get the boost back past 10 psi and i can hear a small leak or somthing but i cant find it,, somone told me you need to put a gasket between manifold and the turbo ,,,there wasent 1 there before but ya never know.. tnx for your in put ( stock turbo from a stock turbo 86 gn origenal elbo and down pipe)
The surfaces between the turbo and exhaust manifold are machined surfaces and did not require a gasket (kinda like installing a cast iron exhaust manifold on a sbc or bbc). But you could use the gasket from a turbo riviera. Also, I have had luck using a 2.5 inch hedder colletor gasket. The one I would recommend is the MrGasket ultra seal part #5980. You can get it from Kragen Auto Parts. It is a composition/graphite impregnated steel shim gasket.
Buy a gasket from Cottons Performance.
GAS110
3 BOLT TURBO GASKET
This is the gasket that seals your turbo to your exhaust header. Sealing this gap will increase turbo spool up time, steady your boost and enhance performance
$ 11.95
http://www.cottonsperformance.com/index2.htm