71 Blazer tranny crossmember Question??

[chevy111]

I have a 71 k5 blazer. It came stock with a TH350 tranny and 350ci engine. I am wanting to put a big block in and want to change over to either a th400 or a build 700r4. Has anyone done this and is there a difference in the crossmember. If so where could I find a crossmember. Also will the 205 transfer case bolt to a 700r4?
Thanks,
Kirk H.

 

[thatK30guy]

Keep the stock member you have. It will work no problem.

 

[sweetk30]

as long as the tcase adaptor is the tall one it will work. just need to move it back on frame and drill new holes and bolt in and go. the shifter link will be same place and will clip in. good luck.

 

[chevy111]

crossmember

So the stock crossmember will work for a th400 or 700r4. Which tranny will I need move the crossmember for?

 

[sweetk30]

So the stock crossmember will work for a th400 or 700r4. Which tranny will I need move the crossmember for?

th400 longer than 350. and th700 vary close to th400. as you go bigger than 350 it moves the member back. only by up to like 2" max tho. plenty of room. just put in what you want. then bolt member to adaptor. clamp to frame mark holes drill then bolt easy.

i got supper lucky on my swap out came 400/203 in went 4l80-e/205 . found rear hole in frame was exact with front hole in member.