I found a complete 1966 390 but it is out of a truck, I think an f150. I was just wondering if anyone knows how much horsepower and torque this engine has. I was looking for an engine to put in my 68 cougar. cant seem to find much info on the engine. Any help would be great!

A 390 is a lot heavier and a lot wider than a small block V8. I wasn't aware that any cougars came with any big blocks. Any 352 or 360 or 427 or 428 will weigh roughly the same as a 390, so if your car came with that originally that will not be a problem. The 390 has a longer stroke than a 352 or 360, and cut skirt pistons to clear the longer crank counterweights. The truck will have unimpressive horsepower figures as the distributor installed will have centrifugal advance limited to produce more torque at lower rpm. Truck level torque typically requires a 10.5 or 11" clutch to prevent early burning. This requires a granny low 4 speed or 5 speed trans to match the super size bell housing. Good luck on finding one of those not worn out. The truck heads will be lower compression than car heads, and the exhaust valves may be sodium filled to inhibit valve burning. These require special handling at scrap time. The engine blocks are pretty much identical 352, 360, 390, 428 car or truck. Of course, you can change distributors and intakes and exhausts to produce any horsepower you want up to 400 without special racing parts. The 390 is a real case of wretched excess these days unless you are hauling a 6 horse trailer loaded over the continental divide, but it's your money, buy what you want. Most of the fuel inefficiency will come from the mismatch of the carburator to the fuel they sell these days, I've had to equip my small block V8 with a 4 bbl racing carburator with custom jets to get any kind of mileage at all. Profossional carb rebuiders are prohibited by the EPA from rejetting the carbs they sell for modern gasoline, they have to sell the old carbs jetted for the gasoline they stopped selling in 1982, so for example, wreckers with big blocks get 1mpg now when they would have gotten 10 mpg on real gasoline. Good luck.

This post has been edited by Indianajo: Feb 9 2010, 04:48 PM

The only Cougar that I know of that had the big block was the Eliminator and it had a 428 Cobra Jet FE Engine. I don’t know if you want to build a Hot Rod or stay with a stock appearing car but one thing you need to be aware of is, the unleaded fuel is hard on valve seats. You can modify the 66 heads with hardened seats or you can buy after market alloy heads with the hardened seats already installed.
The horsepower on these old 390 engines was somewhere between 250 and 275.