The factory 350 V8 engine and Turbo Hydramatic 400 transmission removed from the HQ Statesman was transplanted into the GTS. Fortunately, the Statesman was unmolested, especially the engine – all special clips, brackets, heat shields, ADR-27A pollution gear were all still in place. The engine appeared never to have been reconditioned and cylinder compressions were all above 150 PSI so reconditioning was put off to another day. Every oil seal was leaking so all were replaced including welch plugs. The heads were not removed.
The Rochester Quadrajet was disassembled, cleaned and new gaskets installed. When the engine was finally dyno-tuned, the Qjet throttle body was found to be warped from overtightening its 4 mounting bolts over the years and required straightening. The throttle shafts needed to be re-bushed. Interestingly, the original factory spec primary jets and secondary metering rods were still in place. Both were changed during the dyno runs to achieve optimal power / economy. The original Delco points distributor need a replacement shaft due to wear of the original. The camshaft was rated as moderately worn but still good enough.
Following the dynotune, performance improvement was very evident throughout the rev range. The previous very brief “chip” from the back wheel spin at the 1 – 2 shift was now much more “vibrant”
I used the same exhaust shop as I had for the LS 350 dual exhaust system. they are able to bend up a set of from engine pipes from a single length of tube without joins as per the factory spec including the cross-over tube. A new exhaust heat valve (still available in the US) was installed that closes off the RHS exhaust outlet and forces the hot exhaust gas back through the inlet manifold to increase cold start fuel vaporisation. These valves are almost always missing from surviving 350s but they work fine and are fully open once the engine reaches operating temperature