Changing 700R4 to NV4500

[johnanc]

Taking a recently installed 6.5 w/ <10K miles in an '84 blazer and putting it in a K2500 w/ NV4500 manual transmission. I see there are (6) 10x1.5 bolts connecting bellhousing to the engine in the Blazer but there are (4) 12x1.75 bolts connecting the clutch assembly to what appears to be the back of the engine itself. I have been told that there is an adapter plate between the clutch assy and the back of the engine. If my truck needs anything more let me. Originally Posted by johnanc
Am attempting to take a 6.5 (model 506) attached to a 700R4 out of a '84 Bazer (I replaced a worn out 6.2 with the 6.5 a couple years ago in that vehicle) and put it in a '94 K2500 with a NV4500 I bought recently(has a massive coolent leak into the oil so thought I'd use the 506 6.5 since it has only ~10K miles since uncrated). I don't have much experience with manual transmissions (last one I worked on was a Honda quite a while ago) but noticed that the NV4500 only has (4) 12 x 1.75 bolts holding the the clutch assembly to the engine (I'm supposing those 4 bolts went the whole way through the clutch housing in to the back of the engine) while the 700R4 has (6) 10 x 1.5 bolts attaching the bellhousing to the back of the engine. I haven't had a chance to pull the K2500 engine out yet but I'm already afraid this isn't going to work. You seem to be pretty knowledgeable...is this not going to work!?! Thanks, John

[More Power]

GM did switch from SAE to metric bellhousing bolts in the late 90's. While I don't have any experience working on a manual trans equipped 6.5, the new engine should work with the NV4500 clutch assembly.

Jim

[Hubert]

You may want to edit your post I was a bit confused reading it.
Not sure what bolts you are talking about. I think you are referring to the 4 bolts that attach the bellhousing to the NV4500 case. The bellhousing to motor bolt pattern is the same for 6.5's. Just the minor SAE to metric change mentioned IIRC 3/8 (0.375) 10mm = 0.393" not really much bolt change. I have never seen any note of the holes in the bellhousings being different.

Note there are different flywheels (solid vs dual mass) clutch discs, and slave cylinder setups for various years. But as long as pieces are compatiable everything should be ok.

Someone feel free to correct me if I am wrong.

[HH]

IIRC that is right. You need a bellhousing which bolts to the engine like the auto trans and the NV4500 bolts to the bellhousing with the 4 bolts. You will also need a pilot bushing/bearing.

[NH2112]

Last November I installed a 99 6.5l into an 85 C1500 w/SM465 manual tranny and all I had to do was bolt the tranny up - no adapters required. Any Chevy/GMC tranny used in trucks will bolt to the 6.5l or any other SBC, BBC, or SBC-based V6 (i.e., 4.3l Vortec.)