305 v6/3 spd on tree swap to 350/350

[moovinmetal]

does anyone know if the original GMC 305 v6 monts attached to the xmember will place the 350/350 where it needs to beor will i need different moounts and if so what will work? Thanks Jack

[markeb01]

If you’re asking if the GMC bell housing crossmember will correctly position a Chevy V8 engine, post #2 on the following thread, claims the crossmember is the same for GMC and Chevy but the truck in question is a 1965. In looking at photos it appears the rubber Chevy bell housing mounts themselves are different than the GMC, but “probably” fit the same on the crossmember. This doesn’t definitively confirm the crossmember is in the same location however.

http://67-72chevytrucks.com/vboard/s...ng+crossmember

And here’s another thread with somewhat confusing information that might provide something useful:

http://67-72chevytrucks.com/vboard/s...ng+crossmember

Hopefully someone than has actually done a GMC V8 swap and retained the original GMC bell housing crossmember will chime in.

OOPS - didn't catch the part about the 350/350.

[Captainfab]

Since it sounds like you're planning on converting to a TH350 auto trans, the bellhousing crossmember will need to to removed. As for the V6 motor mount brackets, no they will not work with a small block. It appears you have a '64-'66 GMC, so you can use the '63-'66 motor mount brackets. Let me know if you need a set of original style ones.

Originally Posted by moovinmetal

does anyone know if the original GMC 305 v6 monts attached to the xmember will place the 350/350 where it needs to beor will i need different moounts and if so what will work? Thanks Jack

[moovinmetal]

Thanks for the info. The trans xmember will have to be cut out but, it sounds like the motor mounts where they attach to the front xmember may have to be for a v8 is this correct? there are 2 sets of holes will i need to reposition the mounts or due to the diminsions of the LARGE v6 block are they to be left in the original position? Capt fab how much for yours if needed and shipping to 63361

[Captainfab]

The V8 and I6 mount brackets are the same for the '63-'66 trucks, except for the 292 I6. They were originally bolted in the rearward set of holes. Some guys seem to have issues when running a HEI distributor and the engine is in the stock location. Myself I've not had any problems. One solution to that is using the '67-'71 small block brackets. Those bolt into the forward set of holes.

I have either set of brackets.....$45.00 to your door.

Originally Posted by moovinmetal

Thanks for the info. The trans xmember will have to be cut out but, it sounds like the motor mounts where they attach to the front xmember may have to be for a v8 is this correct? there are 2 sets of holes will i need to reposition the mounts or due to the diminsions of the LARGE v6 block are they to be left in the original position? Capt fab how much for yours if needed and shipping to 63361