Manually rotating SBC without plugs

[krcaddis]

I'm ready to find TDC on my crate 350 and install a timing marker. I pulled all the plugs squirted a bit of Marvel Mystery Oil in to lube the cylinders. (Heads are on it). I had to swap harmonic balancers to get the crank pulleys to align with the accessories (Alt. Smog Pump, Water Pump, PS, AC). It takes quite a bit of effort to rotate the engine IMO, 47 ft lb using a torque wrench on the crank bolt. Is that too much?

The engine sat a long time before I bought it and once I set the TDC marker it's ready to drop it in place.

I suppose this would be the best time to install a 700R4 in place of the TH350, though I'm not sure it's worth the cost ($99 at Pick'n Pull!) which would likely need a look over in a shop at least. I've read that an '89 doesn't require a computer. Or a different driveshaft or flexplate.True? Advice/tips?

 

[Honky Kong jr]

I don’t think that’s to excessive. Even with out compression your still moving 8 pistons in their bores. I would say it might be if you had ported pistons but I highly doubt you do lol

 

[1987 GMC Jimmy]

I don't think it's excessive either. I was turning mine over today at sixty with the plugs in. And no 700R4 requires a computer if that's what you're asking, but the computers do control when it locks up. Before 1987 in the trucks, they used a vacuum controlled lockup circuit, which your truck should have anyways if the transmission is an '80 model or later. I think it's worth it to swap, but I would not get a transmission older than 1987, and I would 9 times/10 deem any transmission you pull out of a junker a rebuildable core and not a turn key transmission because you don't know what all it's been through, and 700R4s are easy to destroy if whoever owned it knew nothing about them.

 

[shiftpro]

If anyone knows better please correct me if I'm wrong, I believe the 700 is one of the more expensive trans to rebuild. It certainly does cost more to beef up than say, a TH350 or 400.

 

[CSFJ]

If anyone knows better please correct me if I'm wrong, I believe the 700 is one of the more expensive trans to rebuild. It certainly does cost more to beef up than say, a TH350 or 400.

They always were. The price seems to get expensive quick once you get more than 3 forward gears. Cant imagine what the newer 6 or 8 speeds would be to rebuild, once they're out of warranty.

 

[Honky Kong jr]

If anyone knows better please correct me if I'm wrong, I believe the 700 is one of the more expensive trans to rebuild. It certainly does cost more to beef up than say, a TH350 or 400.

I’d take a stock 400 over a beefed 700 all day long for reliability. Here I’m gonna confuse people a 3L80

 

[shiftpro]

I’d take a stock 400 over a beefed 700 all day long for reliability. Here I’m gonna confuse people a 3L80

The best you can expect with a 700 is 500 hp/tq and that will cost about $2000 US alone.
A 400 will hold 1000 hp with about $1000 in parts... and also one of the easiest autos to rebuild... so I've heard.

 

[Honky Kong jr]

The best you can expect with a 700 is 500 hp/tq and that will cost about $2000 US alone.
A 400 will hold 1000 hp with about $1000 in parts... and also one of the easiest autos to rebuild... so I've heard.

I do like a Glide too, but they are costly as well to build to hold up to the abuse of a lot of HP.

 

[rpcraft]

Is your motor new? If so then why put a used 700R4 behind it. do you have the money to afford a rebuilt one? I'm not sure I would really ever trust a 700r4 out of a wrecking yard unless it you happen to stumble across one that has really low miles on it.

 

[bucket]

Trust a 700r4 only as far as you can throw it. Yeah, you can spend money on one and give it a chance of lasting, but never trust one.

 

[krcaddis]

I posted a different thread aout my horrors with a 700R4 in my '91 4x4 and I'm wary of them in general. But I'm tired of 10 MPG in my '85 2X4. The crate I'm putting in a used crate 350 with about 20k miles. I overheated my original engine so I finally decided to replace the engine. I tried to sell it as is; no one would give a decent price for a 41k mile '85 although otherwise it was like-new. I bought a Taco but found it too small for a ranch truck, but ok for a run-around truck. The right engine finally showed up at a good price, and 265 hp. NOW, can I get better mileage too? It's not a 4X4 hopefully just a solid, long lived work truck for a70 year old. TH350 or 700R4?

 

[Jerry phillion]

You are not going to get probably more than 2 mpg extra. By the time you figure all the costs to change over , as mentioned before, is around $2500. At 5000 mi / yr you would only save
A couple hundred a yr. To me it isn't worth it. The 350 is a
Much better trans for what you use it for. Just my .02.

 

[4WDKC]

700r4s arent bad transmissions, I have 2 one in my vette behind a 406 and one in my truck. THe vette has a bowtie overdrives stage 3 rated to 600 tq, have not had a single problem with it. The truck has what I assume is a stock 700 and its hurt, PO damaged the mount for the tv cable and has bad stuff in the pan but, it still works flawless. I plan to tow with the truck so it will be swapped to a 4l80 when the 700 dies. Something to think about a junkyard 4l80 is the same as a 700r4, cost about the same to rebuild (700 better than stock/4l80 stock rated to 450tq) you can pull a 0411 ecm and harness from a truck in the junkyard and convert it to transmission controller only mode. Now you have a stout overdrive tranny, you're not using the efi part of the ecm so minimal wiring. 91 Speedo should be able to use the output from the ecm, this would have been my plan if I hadn't found a vortec 454 and tranny for a reasonable amount.