Originally Posted by Trucknut
Could someone tell me if Chevy made an LT1 in 1986? I'm looking at one with an AT that is said to be a 1986 with 76,000 miles on it. Supposedly from a Z-28.
LT-1 is from 70 thru 72, it is a 350 inch Gen I small block.
LT1 (see the big (dash) difference in the name) is from 92 thru 96. It comes in 350 inches and a bunch of power outputs depending on vehicle year and model. There are aluminum heads used on the 'vette, Camaro, and Firebird and cast iron heads used on the Impala, Buick Roadmaster and a Caddy. There is a kissing cousin, the L99 of 263 inches and all iron that is often confused with being an LT1, it isn't. It shows up in B and d bodies so you've got to investigate which displacement you're looking at before plunking down your Visa card. The L99 uses a 3 inch stoke stuck in a 350 block one could come up with an injected, reverse cooled 302, food for thought. But both engines (LT1 and L99) are considered to be GEN II small blocks. They are injected from complex to really complex. They have the Optispark distributor on their noses. They are reverse cooled, heads first then block identified from the outside with a really gompy looking water pump and no radiator return hose from the intake. The L99 heads are the same design as LT1 but only in cast iron with smaller valves to fit the 3.74 inch bore. The heads can be made to interchange blocks between the LT1, L99, and LT4. however, they do not backdate to GEN I SBCs though the bolt pattern is the same, the coolant passages are not.
The LT4 was made for only two years 96 and 97. It looks a lot like an LT1 on the outside. It came with more cam and compression, bigger valves and ports, and with many of the Optispark's problems fixed. It comes only in 350 inches with aluminum heads that feature even better combustion chambers than the LT1 and have the usual bigger stuff as mentioned, plus they include roller 1.6:1 extruded aluminum rockers on bigger, but metric, studs.
Is this a great country or what?