Well I got the 454 & 400 trans in. I used a stock GM 200R4 crossmember just modified drivers side to clear dual exhaust and headers. Also used an off set trans mount only because the trans mount plate on crossmember is at at a angle I also put a hose clamp around trans mount to keep it from coming apart. The crossmember works and fits perfect. I dont have to use any frame extensions. I had a lot of fun making stock colum shifter work and to get around headers and a BBC install. I also installed a BBC 454 .30 over. I used Headman Headers that fit well only had to do alittle grinding on frame on pass side and small ding on drivers side header to clear stock motor mount. Beats paying $500 for the Hookers Headers for G body with BBC install. Also save on aftermarket crossmember there not cheap. I will leave in heater and ac on firewall. You can only use stock height valve covers when you leave ac and heater intact. Would post pictures but dont know how. If any one needs any info on how to Install a BBC and 400 trans in a 1979 ElCamino just ask. Thanks for the replies. This camino will be a beast and a blast to drive. And best part it looks stock. Dave