Dartht33bagger

Let me preface this with the fact that I'm not really a hardcore gearhead. I love my car and I work on it whenever something breaks, but I honestly don't much about motors. I've tried to do my research, but I get fairly lost in most of the threads once people go off about cam lift and valve sizing, etc.

At 172k miles, my 305 has finally given out. I had hoped to limp it along a few more years until I move out of my parents house, but that isn't going to happen. What I need to do now is figure out what way I want to go. My requirements for this build are:

1. Keep it Oregon emissions legal. This is required.
2. This car will never see the track or the drag strip. It's only a highway cruiser. Mid-high 200s for HP and low-mid 300s for torque would be fine. Even stock numbers would be fine. I've always enjoyed driving my car. I definitely do not want a 400 HP car.
3. The motor has to work with the 700R4 transmission and the original rearend.
4. In tandem with 1, I want to keep the TPI on the car.

Over the past 6 years of owning this car, I've done some sporadic research on what it takes to put a 350 in these cars. From my understanding, a 350 swap includes:

1. Finding a 350 that has a 1 piece rear main seal and 87-95 heads to fit the TPI intake manifold. The heads also are center bolt instead of perimeter bolt valve covers.
2. Buying 22lb injectors to replace the 19lb injectors.
3. Buying a 350 knock sensor.
4. Finding someone to retune the computer.

Step 1 isn't bad in the 1 piece rear main seal aspect since I can find crate motors with them on Jegs. However, the heads are an issue. Either I don't know what to look for or they don't exist, but I can't find any crate motors that come with the 87-95 style heads. It almost seems like my best option here is to buy a short block and find some heads that would work that aren't really expensive race heads. Steps 2 and 3 are no issue. Step 4 is another question mark for me since I don't have any idea who to talk to in order to get the computer reprogrammed.

This is where things get messy for me. In my past research, I haven't been able to figure out how to put all the pieces of a 350 swap together. Step 1 and 4 above are above what I've been able to figure out doing research. I'm almost leaning towards just rebuilding the transmission and the 305 and calling it a day if I can get it done for a good price.

Night rider327

iTrader: (13)

1st, what is wrong with your 305? 172K miles is kinda low for the engine to be shot. If took care of all sbc engines will go 225K+ miles.

Most of your std. crate engines from jegs/summit, etc will have vortec heads now, or large chamber pre 87 type heads, or aftermarket heads that will mostly be pre '87 type.

You can buy an aftermarket TPI intake base to fit vortec heads or the 55-86 style but the intake can run upwards of $400

You are not looking for massive HP here so look at jasper or some of the other rebuilders and buy a rebuilt 87-95 350

Dartht33bagger

Thanks for replying!

The engine has always burned some oil. I bought the car with 153k miles on it. From day 1 it puffed out blue smoke on startup. About a year and a half ago it started burning oil really bad with huge clouds of blue smoke out the exhaust under acceleration, so I had to change out the valve stem seals. About 4 months after that it started pushing oil out of the filler cap and PCV. Changing out the PCV didn't help. It's progressively gotten worse over time to where I have to put in a quart of oil every 500 miles or so. The oil that pukes out onto the valve covers burns, so at stop lights I see some smoke wising out of the hood and can smell burning oil through the vent.

The final kicker: recently it has been making a metallic knocking noise at idle. I had my grandpa come over and look at it since he was a mechanic for 40 years and told me it's a bad ring. If I pull the oil filler cap off and put my hand over the hole, I can feel pulsing air, which he said means the rings are shot. I'll also include a picture of the oil puking out all over the driver side valve cover after driving the car to work yesterday.

This all seems a bit odd to me since I really do baby the car. I rarely go above 2200rpm when driving it and I change the oil regularly.

Your statements do confirm that the 87-95 blocks are hard to come by. I have seen that adapter intake for vortec heads but it seems really expensive for what I'm trying to do. It's an option to keep in the back of my head. I guess I'll just keep looking around and see if I can find anything. Do you have any idea how to go about getting the computer retuned? I'm a computer engineer by trade so I could learn how to it myself, but it just seems like a massive time sink from when I've looked into it before.

Dartht33bagger

It looks like most of what I am able to find online for the 87-95 engines are for trucks usually:

1. http://www.high-performance-engines....0hp-p/hp31.htm
2. https://chevroletperformanceparts.co...5003500-trucks
3. http://www.ebay.com/itm/GM-Engine-Lo...-/331754260004

five7kid

iTrader: (14)

Any of those would work. The main advantage of the first one is it used a roller lifter cam (that's what they claim, anyway).

Dartht33bagger

I stopped by a local machine shop and transmission shop that my Grandpa used back in the late 80s to put together his 454 Blazer. Both of the shops have been around forever. The quotes I got were:

1. $3000 for a total rebuild on the 305. Bored out block, new balanced pistons, rods, cam, valves, shaved heads, etc. Everything on it would be new. The price seem really steep though since I was seeing estimates of $1500 for a 305 rebuild on here.
2. $1000 for a 700R4 rebuild with higher end torque converter, clutches, bands, etc than stock. This was more about what I was expecting.

The steep price of that 305 rebuild is putting me off some. A $1500 305 rebuild and then throwing it back in without having to deal with the reprogramming the computer sounds nice. A $3000 rebuild doesn't sound nearly as worth it money wise (but still is time/expertise wise).

Five7kid, with the first motor I posted above I noticed that it looks like the oil filler cap and pcv valve are on the passenger side of the motor. My current 305 has them on the drivers side. Is this an issue at all? Also, with that motor, will I have any other drivetrain issues if I go that route? I seem to remember reading years ago that the 700R4 blows up above 350 ft'lbs of torque and that the stock 10 bolt rear end is pretty weak as well. I don't really want to have to redo my entire drivetrain just accommodate the new motor.

While the 350 swap in general is more appealing, the tuning part looks like a money pit all on it's own. In my initial research, it looks like I'd have to buy:

1. New 22lb+ injectors, knock sensor and ESC module - about $200 maybe
2. An Ostrich emulator to speed up tuning time with less iterations - $180
3. A wideband O2 sensor - $180
4. EEPROM programmer - $80

That's another $600 just in programming materials - not even including the time I'd have to invest to learn how to do it.

And then of course there is always the $5k+ LS swap possibly that seems the most complicated of all of my options.

Engine swaps on these cars are a nightmare for an engine newbie like me

Night rider327

iTrader: (13)

I'm not understanding your trouble man. You just want a mild driver. Stick a 350 in there with your TPI intake, larger injectors and knock sensor and a factory 350 TPI ecu. Just be sure to use 87-95 center bolt heads.

Myself I would look on craigslist for a low mileage vortec 350 from a 96-2000 truck/suv that was wrecked. You can pick up a complete engine for $400-800 with less than 140K miles on it. Heck I have seen them with less than 90K

Buy the vortec TPI intake base and the parts you need and still come out around $1500 or so.

FireInMe17

I agree with night rider, that's how I got my engine but I ponied up for brand new vortec heads. But speaking from experience, find the lowest mileage 350 vortec that you can. I've heard of the heads cracking around 160-170k miles. I bought one with 163k for $100 hoping it would work in my K5 but when i took it apart the heads were starting to crack so no good.

Get on sdparts.com and get their vortec tpi intake manifold, they run $400 but well worth it to use vortec heads in these. I had to make a block off plate for a port in the back for mine but no big deal.

If the engine is good and you can hear it run even better. Then you can just take it apart down to block and rotating assembly to check it out, but if it all checks out then new gaskets and head bolts and throw it in the car.

Things to check for are cracks between the center combustion chambers on the heads, vortecs crack there. And check for piston ridge at the top of the cylinders. That will indicate bad rings and the only proper way to fix that is an overbore. If there's no ridge that you can feel with your fingernail then it's good. If you can still see opposite 30 degree hatch marks on the cylinder walls then that means the rings are not worn at all and still good to go so you don't have to do anything with the bottom end of the engine.

Once you get past that, put the engine back together and put it in. Get in contact with Scott Hansen at scotthansen.net/index and have him make you a memcal for the 350 so it will run right like I said in the other thread you responded to.

As for a transmission, I would just put in a shift improver kit to help it along and get an ACC Boss Hog torque converter and it should be alright for awhile until you can get something else. Torque converter runs about $285 from summit and the shift kit for b&m is $50 from summit also.

That should get you at least 275hp and upwards of 350 ft/lbs and you'll be happy. Best thing you have going for you is that you already have all the TPI stuff you need minus the larger injectors, 305 uses 19lbs/hr and 350 is 21 if I remember correctly. But it's all in what you want to do.

That's about the best and cheapest viable option that i can think of.

Just be careful when looking for engines, for it to be a true vortec engine, the casting code on the block should be 880, and the heads are 062 or 906 last three digits.

dmccain

iTrader: (2)

Or buy a brand new Vortec engine from Summit or Jegs for around $2100.

Dartht33bagger

I'm continuing to snoop around a little bit day by day and have added quite a bit of information to my engine swap document I've been keeping notes with. For the last day or so, the L31 crate from Jegs was my target. $2050, vortec heads, and pretty much a direct bolt in was selling me. And after seeing that all of the same accessories and parts would work from my 305, I thought I had my engine choice squared away.

Until today. I came across a thread that informed me that vortec heads do not have the exhaust bypass holes needed for EGR. In Oregon, the inspector does not open the hood during smog testing. They check if the cat is there, and then stick a sniffer in the tailpipe. From what I've gathered, they only check hydrocarbon levels, since my NOX and CO levels have always above the "pass" level on the sheet when I've passed with my 305. Which leads me to believe I may just be able to delete the EGR since it seems impossible to have an EGR on vortec heads. Since I'd still be retaining my cat and A.I.R. system, I don't think emissions would be an issue, but I'm not entirely sure if the EGR is something I really want to remove if I don't have to. I guess there is always the option of routing the external EGR from the exhaust manifold as well, but I'm not sure how that would go with either the Hooker 2055 or Dyno Don headers.

In the meantime, I'm going to call ATK about this engine this week and see if I can get morei information on it. I'm also going to stop by local Chevy dealers and see if they have any 87-95 crate motors available. It might just be worth going the 87-95 gead route since it would cost the same as the L31 after I factor in the $400 TPI vortec intake manifold for the L31 and I would get to keep the EGR.

Night rider327

iTrader: (13)

I'll see if I can find the part number but there is a factory type carb spacer plate with built in in EGR mount. It would fit between intake and carb and EGR valve mounts right off the side of plate.

five7kid

iTrader: (14)

'86-1/2 to '92 Vettes had aluminum heads that also did not have the exhaust cross-over passages built in. The factory tapped off the exhaust manifold to provide exhaust gases to the EGR valve (these were all TPI systems).

GM also had an emissions-legal crate motor kit based off the ZZ4 engine, which used the same aluminum heads. The kit included a similar pipe that tapped the exhaust manifold and routed gases up to the intake manifold to feed the EGR valve. The pipe went to the "hot air choke" boss that was cast into the ZZ4 intake manifold. Later they deleted the pipe and EGR valve from the kit because they realized the ZZ4 cam provided sufficient overlap to basically do the same thing that the EGR valve did for NOx levels.

A Texas GM dealer called Scoggin-Dickey offered a "HO 350 TPI" crate engine a few years ago that used upgraded Vortec heads (better valve springs), used the GM LT4 Hot Cam with 1.6:1 rockers, and an Edelbrock-made Vortec TPI base. They had a kit that again tapped off the exhaust manifold to feed the TPI EGR valve. I don't know if they still have that kit available, but you wouldn't have to be using Vortec heads in order to utilize it.

The ATK engine you linked, according to their information, uses TBI "swirl-port" heads. They will be power-limited, but should actually work well with TPI since they're both designed for low-RPM operation.

Dartht33bagger

I saw that mentioned in some threads, but it doesn't help me much since I plan to keep the TPI. The SDPC TPI vortec base has a section in the installation manual about routing an external EGR from the passenger side exhaust manifold, but that seems a bit goofy to me.

What I'm trying to figure out is why chevy removed the exhaust passover holes from the vortec heads. Apparently EGR was not needed for some reason, so it incorrect for me to assume that somehow the vortec engine are able to keep NOX levels down without an EGR? Or did the vortec trucks have something different than EGR that kept NOX levels down? Somehow the vortec motors had to stay below the emissions standards.

five7kid

iTrader: (14)

They were only used in trucks, which (at least in the past) had different emissions standards than passenger cars.

EGR is only for NOx reduction, which, if you meet the requirement without it, makes EGR moot.

Dartht33bagger

Well I'm pretty much convinced on picking up a L31-R crate motor and some Dyno Don headers. It seems like the best bang for my buck. Other than the SDPC vortec TPI intake and the cam position sensor hole I have to plug up, everything else should just be a direct fit right? The oil pan that comes with the motor should clear the crossmember and all of my sensors/accessories/smog pump should just bolt right up correct?

I'm assuming the AIR system needs to stay on the car as well to pass emissions? Or did vortec motors do away with that and still pass emissions? Just having a cat would be ideal if I could get away with it lol.

Dartht33bagger

L31-R ordered today. I'm ready to get this swap started here in about a month

AW119 Pilot

iTrader: (1)

Just a thought. Get the Oregon Special Interest plates. Problem solved no DEQ. Build baby build! My plan.