Like TurboPhil said, the only problem could possibly be the floorpan, but I doubt it would be an issue. The elcamino frame is basically the same as a regal, but it is actually missing some of the stiffening braces that are located at the upper control arm mounts on the frame itself. These braces look like they were designed to give support for a higher torque load on the control arms. Anyway, if you put in the GNX suspension, there would be no need for that extra bracing because the GNX does not use the upper control arms. The back seat cross braces wouldn't be needed either because an elcamino body itself has much less flex than a regal body. There is a guy on ebay right now selling a GNX rear end cover and torque arm that i was thinking about, but i think its gonna be out of my price range. I have a elcamino transplant that is 95% done right now, and i was thinking that the GNX suspension would be cool, but for $2000 in parts, i'm gonna just stick with the GN rear that is bolted in right now. You do however need to shorten the driveshaft when you bolt in the 8.5 rear because the 8.5 pinion is longer than the 7.5 pinion. Also, like someone else said, get a 4.3 liter elcamino and the fuel pump will already be in the tank with all the wiring factory installed. Oh well, I'm going to get to workin on mine right now, Good Luck!! Jeff