I purchased my 1987 Oldsmobile Cutlass Salon late of 2019, with the factory Olds 307 5.0 V8. I swapped the 307 for the Olds 455 a year later. I kept the stock cam changed out the intake manifold, exhaust manifold and edelbrock 750 carb, B&M 2200 stall and rear end differential to a 3.42 posi. I did all of the work myself, it had ran 13.2-13.5 not bad for a stock engine in 1/4 mile. The machining was done by Conrad Racing engines in 2025 in Belville, Texas. The transmission (TH400), I bought from (Doug) Herzog Motorsports in Warrenton, Missouri 2019. Doug, recommended Conrad racing engines while living in DFW, Texas. Both Doug and Ed have been of great help. 2025 Fall, was when I assembled my Olds 455. It has forged pistons and Rods and a roller camshaft. Everything in the engine is brand new. Only issue I had was the valve timing was off when lining up the dots in the timing chain sprockets. I degreed the cam, to match cam card.