What flexplate for newer motor, older trans?

[Bus Ted Knuckle]

I am putting a 1989 model 350 in my 69, hooking it up to my th350. The 350 has the one piece rear main seal, and the smaller bolt pattern on the rear of the crank. What flexplate should I use?

Will one from an 89 chevy truck with automatic trans mate up OK to my stock th350 converter, and work with my starter?

[Bus Ted Knuckle]

anybody?

[extd56]

I got one from a 700R4 from the tranny shop and it worked great. The 89 should work fine, mine was a 91 with a 4L80e so I had to get another one for the 350 that I had.

[svgould]

My th-350 bolted up to stock 1988 TBI motor/flex plate without any problems.

[Bus Ted Knuckle]

Great! thanks guys!

[piecesparts]

I change out my flexplates to a heavier SFI rated plate, whenever I go into a tranny change or engine change. The factory plates have had to many issues with cracking and making have to go back and do the change out on the flexplate. I even had an issue on my 91 Silverado of the flexplate rubbing on my aftermarket starter gear at road speeds. The balooning of the torque converter caused the flexplate to move forward and rub the starter. A heavy duty flexplate (note: with dual bolt patterns) did the trick and the rubbing stopped. The dual bolt patterns covers the different converter patterns.