does anyone know if a 1989 6.2 is the same block and heads as a 94 6.5 turbo. I found a cheap 6.2 and my 6.5 has blown up. will turbo work with this 6.2 ,injection pump, etc..... thanks.. tommy  

A lot of parts interchange between the 6.2 and 6.5, but there are some significant differences. If the 6.5 is a turbo, the engine management is completely different. The 6.5 turbo was one of the first engines GM had with an electronic throttle. In terms of the hard parts, they're definitely "similar" but I don't know if I'd go so far as to say they're the "same."  

I made the 6.5 to 6.2 switch last summer.  6.5 turbo will not fit the 6.2 heads due to the angle on exhaust side,  and 6.5 turbo manifold touches the injector lines (old style injectors) before coming up tight.   I had a 1/4 inch spacer laser cut from steel but havent installed yet. This should set maniforl out far enough to clear injector lines.   Presently the engine runs fine except not sufficient power and smokes black -over fuels- on acceleration. The power problem will go away when I fuel it properly. had to use 6.2 manifold on left bank to be able to accept the 6.5 oil filter base and filter.   Havent connected the oil cooler lines yet. Had to use the electronic injector pump to work with computer and electric shift transmission.  Used the 6.5 thermostat manifold.  Will install 6.5 turbo and manifold soon or have transmission changed from electric shift that of non-electric (may just swap transmissions and install the non-eoectric injector pump and throttle connections. also had to use the 6.5 timing chain cover to get the electric/magnetic pick-up for the computer and etc.    6.5 heads will bolt on and should fix the manifold fit problem  My engine suffered a broken crank and both heads were cracked (170,000 miles).  I have 4x4 1994 suburban. call me if you have more questions.  808-937-9516  and I am in Alaska time. jj  

My 6.5 blew up also (160,000) . I was thinking of putting a 6.2 in. So could I put the heads and manifold from the 6.5 on the 6.2 motor? That way I could use the turbo. My truck is a 94 so it has the electric throttle injector pump etc.