1986350

Hey guys, I'm torn between a decision here. I found a 010 high nickel block in the back of a boat and its sweet. I mean new type on the inside and out. But my car has a 305 with a t5 world class. Now I'm torn between either yanking the 305 out and dropping in a 350 and losing the 5 speed or just selling the motor. What do you guys think? I want more power but I know the t5 can't handle it. So its down to a th350 or the 700r4. I reply would like to keep things original since I know t5 cars are not very common. Please help guys and girls... THANKS EVERYONE.

okfoz

I guess it would depend on what you have... You have a Trans Am (according to your info on the left) And you have a M5, so you would either have an LG4, or the L69...

Ultimately I would look at it like this... If you have the L69, you will have two G's in your VIn, one for the Engine (8th digit) and 10th Digit for the year (1986)... However that is VERY VERY unlikely that you would hae a L69 HO "G" Engine, there was only 26 of the HO's made in 1986... I would say... HECK NO, keep it the way it is... It is too rare, and will be worth much more in the future...

Ultimately I suspect you have an LG4... If that is the case then do what you want.

Drew

iTrader: (58)

It sounds like you're buying into the 3970010 "high nickle" hype... Make no mistake, there's nothing special about that casting number, GM made about a gazillion of them with 4 bolt main 350 blocks being the majority. When you get right down to it, they're just another 350.

Moving on... If you've got a stock thirdgen V8, the earlier 350 isn't a direct swap. Assuming your car is the 85 T/A in your profile, you can probably use your existing starter and flywheel. However, the dipstick location on the 3970010 block is on the drivers side, so your stock manifolds won't fit. You'll need headers to work around the dipstick, also keep in mind the T5's hydraulic clutch slave may interfere with some headers. You'll probably run into just enough headaches in the swap to make it a real PITA.

I wouldn't worry about the 350 breaking the T5. If it happens you can always swap something else in at that time (another T5, T56, automatic, etc). Unless that 350 is rebuilt with different pistons, heads, cam, intake, etc it's probably not rated at much higher horsepower then your 305, maybe less if your 305 is a HO. Drive it nice and it'd probably be fine.

The advantage of the 350 swap, would be the potential for greater power. However, in stock or mildly rebuilt form, smog era 350's didn't make a ton of power. A late 70's truck engine, with an RV cam, dished pistons, large chamber heads, etc wouldn't really be worth the trouble.

1986350

Ok thanks okfoz and drew. yeah I actually just realized my info on the side, I have an 85 not an 86 and yes it is a factory trans am with a 305 4bbl carb and the t5. so building a 350 wouldnt be worth it since its a 70s block?

sofakingdom

iTrader: (1)

If the trans has already been swapped to the 2nd design, then it's already NOT fully "original"; that version of that trans didn't apear in these cars until at least 87.

A 70s 350 block isn't maybe the best platform to build off of, for several reasons.

1. It's ALOT more expensive to put a roller cam into.
2. Your 86 motor will have a 1-pc rear main seal; the 70s motor will have the 2-pc. The flywheel is different. You would have to buy the right one of those.
3. The only size flywheel you can use, is the 12.8". Problem is, if the block is from about 77 or earlier, it won't have the bolt holes for the starter that will fit that combo, and it's not physically possible for such a starter to exist, because in order for that to occur, the inner bolt (closer to the crank) would have to go RIGHT DIRECTLY THROUGH THE MIDDLE of the starter's moving parts.
4. The whole "high nickel" thing is a myth. According to people who worked in the casting foundry, they made those core plates (metal plates that the casting sand is molded to, and the moten block metal is then cast into that sand) as an experiment, which didn't work, and then they ended up using the same group of plates on ALL the blocks, which were ALL cast out of the same metal ANYWAY, regardless of which plate was used.
5. 70s blocks tend to be chock-full of quality control problems that are anywhere from expensive to near impossible to fix. The most common in my experience are The Starter Bolt Problem (about a third of them), where the starter bolt holes are too far from the crank, making the starter always struggle to start the car and make that horrible grinding noise, and it gets worse when you shim it; The Lifter Bore Problem, where some of the lifter bores don't point straight at the cam, and therefore it wipes out ANY cam you put in it; The Dowel Pin Problem, where the bell housing dowel pins aren't centered on the crank, which makes the motor eat pump bushings and clutch gear bearings; and The Cylinder Bore Problem, where the cylinders either aren't centered over the crank journals, or they aren't perpendicular to the crank.
6. That block will have the driver's side dipstick, which won't work with the manifolds in these cars. While far from an insurmountable problem, if you were planning on using those manifolds (no others will work), that's more money and aggravation you have to spend to overcome the mismatch.
7. The naked BLOCK is the ABSOLUTE CHEEEEEPEST part of the rebuild. It's cheeeeeeper than the gasket set. Even if you get it FOR FREE, its cost is so trivial, it's completely down in the noise. Even assuming that it DOESN'T have any of those Problems above, or some others like core shift or just generally crappy machine work (decks that make some cyls .010" OR MORE taller than others for example), fixing the flywheel and starter bolt hole mismatch will cost more than a whole other block, meaning, that FREE block will cost you MORE than going out and buying one.

There is no point whatsoever in NOT starting out with the best one you can get. That means most easily, one out of a 87-up TBI or CPFI truck; unbelievably common, cheeep, and eeeeeezie to find. TBI ones (87-95) mostly come with roller provisions in some partial state of finish, and you can easily enough get the roller apparatus to put in it; CPFI ones (96-00) have the complete roller setup. So, for $50 - 100, you get rollers, instead of spending $400 on the original style roller lifters.

Other than that, it could be a perfectly fine choice.

Hiemarch

iTrader: (2)

it would be worth it but i would not be cheap, you're looking at changing the heads to a smaller CC and putting flat top pistons to get your compression up to around 10:1 instead of the factory 7.5:1 that those years are known to have. now you saying that it was a marine engine could be a good thing, if its a Mercruiser chances are verry good that you have forged internals due to the marine environment which is a good thing, so a head swap and nice cam would wake it right up for an automotive world.

and if you are thinking of going for the swap GO FOR IT your car is only worth what you want it to be worth, are you selling it any time soon or do you want to make it your own. what you can do is what I've done is yank the motor build it up the way you like and properly store the original motor if you have the room. that way the swap back is easely accomplished

Drew

iTrader: (58)

To clarify a little since it's still not entirely clear... 1985 and older = 2 piece rear main seal, 1986 and later = 1 piece rear main seal. The 3970010 blocks I've seen have a 2pc rear main seal, with the main seal change, the crank changed so unless its the same rear main seal the flywheel has to change. All thirdgens use a 153 tooth flywheel, early blocks aren't drilled and tapped for both starters, but the 3970010 blocks I've seen have both sets of holes. If the block has both a straight pattern, and a staggered pattern, the starter shouldn't be a problem.

Another thing to think about is that boat engines don't lead easy lives. They don't deal with stop & go traffic, but they go from idle to wide open across a lake or body of water, then back to idle. Then they get pulled out of the water and left under a cover, or in a garage, or next to a garage for 9 months, potentially without proper maintenance...

Depending on the origin of the block, and if it's been previously rebuilt, it could have any potential combination of internals. Chances are pretty good that unless someone rebuilt it for performance it's going to be a typical 350 that makes maybe 200hp. Your 305 is making about 150hp. I wouldn't consider the headache to be worth while for 200hp.

As mentioned, if you're going to spend the money, get a late 80's-mid 90's 350 block with a 1 piece rear main, centerbolt valve covers, roller cam, etc and rebuild that. At least then it won't leak oil like a sieve and the cam will survive on modern oils. Of course you'll have over a grand in a swap after a standard rebuild (nothing fancy), and the "while you're in there" parts. To do the job right is expensive, even if Gen-I small block Chevy parts are cheap and plentiful.

I'd probably leave the 305 alone if it runs well. Almost any alternative is going to cost a lot, for a minimal improvement. The hot ticket right now are the LS style engines, so unless you want to go wild or spend a ton of money, or both, I'd leave it alone.

okfoz

Drew,
For some reason I thought that the 1 piece rear main seal was a mid-year change for 1986... I have a friend with an original 1986 305 from his T/A (he bought the car new) it was an early car, I will have to check it for the seal...

John

Drew

iTrader: (58)

I suppose it's possible, but two of the three 86's I've owned had 1 piece rear mains, the third had a 70's 305.

okfoz

Drew...
You may be right... I want to think that the 700R4 (4L60) Transmissions were definitely upgraded in mid 1986 from what I read... I might be getting the two confused...

Like I said, he has a low VIN, made within the first few months, his is in the small group where the 140 Speedo did not have the KM/HR...

John

Drew

iTrader: (58)

Both of the 86 T/A's I owned had the mph only 140mph speedometer.

1986350

Ok guys here's and update. me and buddy yanked the motor and found out that it has a monster of a cam and is a gmt goodwrench crate 350 with the .010 marking. now I know everyone says the .010 is a myth but I don't care. also it has dual starter location bolt holea. now for the things that don't matter. it has a Chrome oil pan fresh brass freeze plugs and a nice fuel pump and Chrome timing chain cover. it also has the heads port matched and polished. at this point it has occurred to me and my buddy that the motor has been worked on and is defiantly custom.

sofakingdom

iTrader: (1)

Interesting reading here, for those willing to put their superstitions at risk.

http://www.nastyz28.com/forum/showth...ght=010+nickel

navy02ws6

Sounds like a nicely built crate engine. Still I really wouldn't pay more for it because of the casting number, if anything I might pay LESS. 3970010 is by far the most common casting number I've seen on cars here at my work. Even in non-numbers matching cars, I see more 3970010s in Corvettes here than any other casting number.

Now, on the other hand, if it were a 3970014, then you would have something a little less common. I believe this was the 'experimental' 350 casting number that is very difficult to find, used in late 1972 cars (according to Corvette by the Numbers), but I've also seen one in a 1977 Corvette that I'm pretty sure was numbers matching. We've had maybe 2 cars that had that casting number.

sofakingdom

iTrader: (1)

014 is the same POS as any other 70s block.

I had one in a 78 Z28, that had The Lifter Bore Problem. (sold the car, WITH yet another cam, to a guy that was JUST SURE he could put a cam in it and it would live, well guess what....) Like any other POS 70s block with GM's top-notch ZERO quality control. Seems like that one had The Starter Bolt Hole Problem too but I don't remember, as I know the cure for that and might well have applied it. THere's no cure (well, no PRACTICAL one, anyway) for The Lifter Bore Problem though.

I remember the # because it wasn't the 010 casting I was expecting to see. I was actually a bit surprised.

If memory serves, that was the one where I changed the cam, and one of the destroyed lifters, wouldn't come out; so I pulled it up with Vise-Grips far enough to get the cam out, then knocked it back in thinking I would put my finger under it in the cam tunnel there and catch it, and then dropped it instead. I heard it plink off of a couple of rods, then plop down onto the pan, but I didn't hear it roll. I was afraid it was still sitting up on the windage tray like part of the pan up front, and hadn't made it to the sump. Sure enough... when I cranked it back up, first thing it did was make a funny "thook" kind of sound; leaked oil mercilessly; and quite to my non-surprise, I got up under it, and there was the lifter, sticking through the side of the pan. I siliconed a scrap of sheet metal over it and drove it anyway, and it was still like that when it finished eating THAT cam just like the one it came to me with, and I sent it DTR.

okfoz

My friends car has the 1 piece seal... I also did a looksie in the parts & illustration catalogs and sure enough, Drew, you are correct, I was wrong, it was all of 1986, according to the IPC that the 1pc rear seal started, not a midyear change....

John

navy02ws6

Right, in anything BUT a Corvette. But we're talking about other GM here, so I stand corrected in this case.

okfoz

I would tend to agree with navy02ws6...

The truth is for the most part, Corvettes got better pieces from the factory than other cars, even with the same part number. They had higher standards. I know that when my grandmother worked for Fisherbody they would make parts for all of the divisions, but Cadillacs in-particular got more scrutiny than other cars... Even when it had the same part number. I have heard the same for Corvettes... Living in Flint, MI has its advantages, I also want to think that when they assembled the Vette motors they actually used white gloves and the whole bit...

John

hardon85

Ok guys this is way off topic but you guys seem to know what you're talking about so I'm gonna ask something I've always wondered. I believe that with the change to the 1 piece rear main seal changed some bolt hole angles were changed. So my question is with TPI being introduced in 1985 is the 1985 TPI system different than the later versions?

sofakingdom

iTrader: (1)

Actually, the 1-pc RMS was introduced in 86, and the different bolt hole angle in the intake as well as center-bolt valve covers in 87.

The heads they used on Vettes kept the 86-back bolt pattern but got the center-bolt VCs.

So, 85 & 86 F-body TPIs have the old bolt pattern, as well as Vettes; 87-up F-body TPIs got the newer pattern.

Drew

iTrader: (58)

86 was the last of the basically old style V8's, with only the 1pc rms to make them stand out. 87-up got the roller camshaft, centerbolt valve covers, altered intake bolt angles, divorced coil distributor, etc.

90_formula_305

Sweet!
Any thoughts on headers for 3970010 2-piece cast blocks? Are the Port-Shape or Bolts patterns of any concern?

Apeiron

Headers don't attach to blocks.