LS3 motor

**ONEslowLS1** · 10-15-2010, 01:58 PM

I bought a 2002 trans am A4 and the guy i bought it from claims he did a ls3 motor swap. So how do i tell if its an ls3 motor.

**98TransAmWs-6** · 10-15-2010, 04:05 PM

If you look at the heads they will be rectangular ports vs cathedral. If you take the intake out it should be flat I believe not the ls1 cathedral style. Also if you remove the valley cover there should be these ports that look like towers down the center, which is for the DoD system but it doesn't come functioning so they are most likely plugged. Another way is there should be a gm stamp some where on the block saying ls3 or 6.2L or something as well as a part number.

**9T8W66** · 10-15-2010, 06:13 PM

6.0/6.2 will be cast into the block (behind the PS Pump).
Check your head casting numbers if they are 241's then likely it's not an LS3.

**ONEslowLS1** · 10-16-2010, 08:50 AM

The heads are 862s

**9T8W66** · 10-17-2010, 04:53 AM

I just did a quick search on 862 heads and it appears their off a 5.3 truck engine.

**jb3golf** · 10-17-2010, 04:56 PM

SO.......WHAT block/engine is in YOUR vehicle!!!????? Did this guy jive you or what?????

**Cutlass** · 10-17-2010, 07:01 PM

Originally Posted by ONEslowLS1

I bought a 2002 trans am A4 and the guy i bought it from claims he did a ls3 motor swap. So how do i tell if its an ls3 motor.

aluminum engine block and heads are one clue.

**Blue_01_Z28** · 10-18-2010, 04:47 AM

The intake if stock should be a 90mm with 4 bolts on the throttle body, Also the fuel rail doesnt have that round regulator between the two banks of injectors.