The first year 1982 HT 4100 engines were rated for only 125 HP and 190 torque which curiously was the same HP and 20 less torque than Buicks carbed 4.1 liter V6 of the same vintage. 1983-1985 full size plus Eldo and Seville saw a 10 gain on both figures or 135/200. The FWD 1985 Deville/Fleetwood curiously dropped back to the 1982 power and torque figures and then in 1986 went up to 130 HP and 200 torque which leads me to believe more power in hiding in these engines than what was advertised at the time. The pellet converters which were on 82 and 83 cars were terrible on flow and the 84 on up change over to monolithic helped a little. A change to the mentioned high flow cat will net a 5-8 HP increase on these engine from the stock factory pellet design and improve power, response and mileage some. The increase in timing and change over to premium ignition parts would probably be worth another 5-8 HP. Stock 1982 0-60 times given for the Eldo with 4100 V8 were 14.5 seconds when new. With the changes above I have seen a drop of over a second or around 13 seconds to 60. the 83-85 models with the extra factory power and torque may be a tad quicker still. Would be interesting to see everyone post there 0-60 times on fortified HT 4100 cars.