Impala SS LT1 to LT4 motor conversion

01/30/06

Burnsville Offroad can customize your street ride as well. What we are doing here is converting a 1996 Impala SS with an LT1 engine to an LT4 using the conversion kit put out by General Motors. The LT4 conversion consists of new intake, aluminum heads, hotter cam and roller rockers. Along with that we will install the GM heavy duty timing chain and gears, a BBK 52mm throttle body, Clear Image Tri Y long tube headers, an F-body mass air, Flowmaster dual exhaust, and a fresh air intake put out by the Impala Superstore.

Here is a shot of the stock LT1 with the air cleaner tube and top cover removed. The car we are working on has only 2200 actual miles on the odometer. It has been stored since new. Here are shots of the new intake, heads and roller rockers. its time now to remove the old parts.

Motor disassembly is pretty staightforward. Intake, heads, water pump and old timing chain and gears are all removed. The new timing chain and gears are installed as well as a new water pump drive gear. Make sure you use lots of assembly lube on the lobes of the camshaft. Line the marks up correctly on the timing gears and then you are ready for the heads.

The heads get bolted on and then torqued to spec. We purchased ARP head bolts to use on this car. The lifters are hydraulic roller already and will be reused. The roller tip rocker arms are put on next. After that the intake and headers are put on. Nothing too hard yet.

Time for some exhaust work. The Clear Image headers are perfect. So are the cats that come with that set up. It all fit perfect. The Flowmaster exhaust fit perfect as well. Flowmaster also included a crossover to tie the two banks together which is a nice addition. The stainless tips are like 3 feet long on this car. The exhaust was fun to do.

Its all together now. The fresh air intake and 52mm throttle body installed without incident as well as the larger mass air sensor. We sent the pcm to Bryan Herter at PCMforless for a reflash and had it back right away. The motor runs flawlessly. I am not so sure it has the claimed 425 HP but it is lots stronger than before. The owner of the car was very happy with the results. When it is all said and done this was an $8200.00 job including labor. Labor cost was about $1200.00 of that. Keep us in mind for all your performance upgrades, whether it is on or off the road.

--Dan