Engine won't spin after flex plate installed and tranny attached

[bruegge]

Hi All,
I have a 1974 J10 with a 401 that was just rebuilt. We've been putting everything back together and hit a snag. After installing the engine/tranny/transfer case in the truck, the engine will only turn over 160-170*. It spun over fine when we installed the distributor (out of the truck), since then we added the flexplate and tranny. My guess it that it is related to the flexplate - the is a light tick that I think I hear from back there when it stops - maybe hitting something on the block?
Any advice or thoughts before I tear everything apart?
Thanks in advance!
Ray

[440sixpack]

Sounds like you have a bolt hitting the flex plate.

Did you install the spacer between the flex plate and the crank flange ?

[bruegge]

Thanks 440, I believe so, but will look. It may be on the wrong side. Will report back asap.
Ray

[440sixpack]

Lots of guys do that, it looks more like a washer than a spacer.

If it's not that maybe you have a bolt head that's too thick. I can't remember how close those run but it's usually not very far from hitting.

[HeavyMetalThunder_81]

That "spacer" is actually a load spreader and goes on the outside of the flex plate. To me it sounds like your torque converter bolt heads are too large and are hitting something or your flexplate bolts are too long and doing the same. That, or maybe your torque converter isn't fully seated in the transmission.

[bruegge]

Thanks guys. Engine is out, flexplate is off. Pulled the pulley and any long bolts running through accessories (getting desperate). Still won't turn over more than 160ish degrees. I will continue to pull accessories and work our way back toward the bare block. If any other ideas pop up, please share!

Ray

[BCRAWLER]

Check your timing chain because I think your piston and maybe hitting a valve. You said in the first sentence the engine had just been rebuilt. Never mind above, just re-read and engine spun earlier. Is it possible something forgien entered intake and made its way to rear cylinder. If something in cylider should only spin 180*..

[bruegge]

Again guys, I appreciate the help. It turned out that the new water pump was interfering with the balancer. Got the engine back in and happy it's not something serious.