Get a new balancer? BOP400 with an adapter? And other problems when you tear down

[dflarsen77]

I've found a million issues with my truck while slowly disassembling over the last few months. It's somewhat entertaining, since I've never had my own where I can make the choices. But there's some stuff I can't find a good explanation and I'm looking for opinions, or comments.

My Harmonic balancer looks done. The elastomer stuff is squeezed unevenly out both sides. It still timed what I think was true before I pulled the engine, but I have read that the outer ring can start to move. Should I get a new one?





So when I pull the engine out, the trans looks weird to me. My neighbor is helping me says it's a BOP th400, buick-olds-pontiac. I get the issue. It's bolted on with a relatively thin looking adapter plate that you can see to the side in the pic. I'm trying to keep my truck build simple, so I'd rather stick with a TH400, even though I realize it's overkill for a stock 350. but I won't have to deal with a different yoke, changing the driveline, etc. Anyone out there think it's ok to keep using this adapter and the BOP400? I'm hoping to sell it for close to the cost of a rebuild-able chevy th400. I've read that BOPth400's can really be 375s, but it has the 32 spline output shaft.





And the oil pan looks like it's been overtightened, most of the holes are puckered up toward the block. Should I try to hammer them flat?




It's smacked in right at the drain plug too, but I don't think it's a big problem:




Anyways, it's been a chore. It's really greasy, like I thought it was painted black. It's that awesome caked/baked style.



Then I saw orange on the front, but then blue on the side. The crank pulley is a 2 groove with an extra 2 groove extension (truck originally had AC, and it's a CA truck, so this is supposed to be normal), and it's just filled with dirt, you can kinda see in the pic.



My neighbor says they weren't painted blue until later, so I figure maybe it isn't the original engine. I looked up the engine code on the front when I first got the truck, V0523TAX, and found it could be at least from around the same year, if not necessarily original, but I figured it was original. After I got stuff taken apart, got the casting number off the back of the block, 3970010, and the head casting number 3932441, I figure it is original, and the specs show it's one of the better 350s available for the trucks.





Here it is after "the first scrape". I used one of the plastic pry tools in a Harbor Freight trim prybar kit. Worked really well, has a wide blade on one side and a skinny on the other.



So it's definitely blue. I only find orange paint on the front. I still think it's original. Maybe they stripped it when it was rebuilt.




So other fun stuff I've found. I have been concerned that it was in a front end accident. It definitely has. I've seen a couple issues. THe Core support is crooked across the top:



The wheel wells are messed up in spots (posted about that before). I'm worried about what all it will take to put it back together, but I'll get there.

But it's a 4 bolt block! Good news sort of:




I've always understood that the iron intakes are heavy, but holy crap. Ended up using my crane to take it off, lol:



I wasn't expecting this gargantuan power steering pump bracket set to weigh so much. This thing is weird, and it was so completely caked in grease, but I eventually got it basically clean. ANyone use this kind? I think I read it was only for 69 & previous.




And finally, it's best to have a helper/buddy (my 14 year old giant son):

[HO455]

Good work and after you get it back in place you will not remember all the work but you will smile every time you pop the hood.
I would definitely replace that balancer. Two reasons. One the rubber is failing as you correctly pointed out and two the snout is very worn in the seal area, which definitely contributed to the oil mess all over the truck. There are ways to help with leaks on seal area of the snout but yours is the worst I have ever seen and may not be fixable.
On the tranny you have be aware T400 BOP transmissions come in two lengths. (The tail shafts are different lengths) I dont know if either of those match a Chevy truck T400. Take some time to measure what you have and see what matches. Otherwise you may have to change your drive line length.
If it is a short shaft T400 it definitely has value a long shaft less so. Short shafts came in A-bodies and F-bodies. Long shafts in the big cars. As far as to if it is a T375 I don't have any experience with those. There is a small chance you may have switch pitch converter version. I would take the time to determine that as they are more valuable.

[randy500]

I can see in the picture he bop th400 is short shaft.
Agreed on replacing he balancer, someone has already installed a stainless steel sleeve over the worn cast iron snout and a new one is relatively inexpensive.
If the truck stays stock I might be inclined to continue to use the bop trans and adapter, it worked before removal so why spend money on it, keep your eye out for a good used chevy th400 cheap and change when found.