A bit over a year ago I bought a beautiful all original 1979 Cadillac Eldorado Convertible, modified under agreement with G.M. to a convertible by Hess and Eisenhardt in Cincinnati Ohio. Original 45000 miles on the odometer. Purchased from 2nd owner and an original California Car. Yet therein lay the problem. Leaked oil as all the seals had dried out. Front suspension bushings dried and cracked, So all seals got replaced as well as the front end gone through + new shocks, complete tune up, etc.
The car was reportedly bought new by a Getty Oil Family member from then Restor Cadillac in Burlingame CA. Ordered with Seville wire wheels from G.M. - Build sheet in hand (stuck behind driver’s door panel : )
The vehicle went to The Rockies with me. Yet here at 7,400’ above sea level there is -25% less air. This means sea level horse power ratings are -25% less here. Ugh. The car is a ‘turtle’. Rated at 170hp sea level, here it is 128hp and a heavy car. So with less air what does one do to increase hp? Less air, so squeeze what there is harder. I.e., increase compression on this ‘smogger’ + other mods.
Presently undergoing the ‘fix’ to bring it up to around 300hp sea level, 225hp here. High compression tricked out heads, stainless valves. polished and ported chambers and full roller valve train set up + free flowing cats and less restrictive exhaust system. This being done while keeping everything ‘stock in appearance’. Not to be a hot rod, just goosed up hp so is adequate. Presently, not.
At high altitude , carbs must be jetted down to their lowest size. High overlap cams do not work as you are asking for more air and there isn’t any. Here one can run 14.1:1 compression on pump gas without detonation to gain more hp. Yet your in trouble if going to sea level. — Shooting for from 10.1:1 to 11.1:1 compression on this smogger with ability to retard timing if going to sea level.
These cars of the mid to late 70’s were underpowered mostly because of the very low compression ratios and the old pellet style Converters. With todays free flow converters they can be made to stay “smog legal” yet still substantially increase horse power. — Effort presently in process. : )