6.5 conversion

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87silveradok20

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Location
Ohio
First Name
Levi
Truck Year
1987
Truck Model
Silverado k20
Engine Size
350
I have quite a few questions about converting a square to a 6.5. Currently my truck has a 350 and a th400. Truck is a crew cab k30 with a/c. First off will engine mounts and what not bolt in (assuming I have to change to 6.2 mounts). I know I need to prepare fuel system to run diesel through it. Will the 6.5 bolt to my th400 and will the th400 hold up alright behind the 6.5? How much can mod the 6.5 before I need to improve transmission. Has anyone kept a/c with the 6.5( body lift maybe?). Probably need 6.2 radiator. I would run a mechanical pump so I don't need computer and that stuff. Is there anything I'm missing?


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highdesertrange

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mike
Truck Year
1978
Truck Model
k30
Engine Size
454
it will basically bolt right in. you need the 6.2 motor mounts. the T-400 will be fine. that's the main trans behind a 6.2/6.5. you will need the diesel torque converter. the AC is fine unless you are using a factory turbo. if using the factory turbo most will use the S-10 AC box. a Banks turbo needs no mods to the AC. the fuel pump doesn't mean you need to run a computer, the injection pump does. any electric pump must be a low pressure lift pump. you need to change the pick up sock in the fuel tank, gas and diesel socks are different. there are a lot of little things you need to do. I am doing this on my 1978. any questions ask away. highdesertranger
 

87silveradok20

Full Access Member
Joined
Jun 29, 2014
Posts
684
Reaction score
138
Location
Ohio
First Name
Levi
Truck Year
1987
Truck Model
Silverado k20
Engine Size
350
it will basically bolt right in. you need the 6.2 motor mounts. the T-400 will be fine. that's the main trans behind a 6.2/6.5. you will need the diesel torque converter. the AC is fine unless you are using a factory turbo. if using the factory turbo most will use the S-10 AC box. a Banks turbo needs no mods to the AC. the fuel pump doesn't mean you need to run a computer, the injection pump does. any electric pump must be a low pressure lift pump. you need to change the pick up sock in the fuel tank, gas and diesel socks are different. there are a lot of little things you need to do. I am doing this on my 1978. any questions ask away. highdesertranger
Ok that lines about up with what I thought. I meant injection pump not fuel pump but anyways. Is there anything that's major I'm gonna need to do?


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highdesertrange

Full Access Member
Joined
Dec 19, 2013
Posts
1,066
Reaction score
211
Location
kalifornia
First Name
mike
Truck Year
1978
Truck Model
k30
Engine Size
454
are you running a turbo? if yes what turbo? highdesertranger
 

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