Hey all,

So make a long story short, it's not looking too good for my 305 TBI atm. I've already done basically all I can to get it running well (short of getting into the motor) w/minimal luck, but simply put, after taking it to a state certified shop for emissions repair, I've come to discover that it's a tired motor that needs a rebuild or replacement (burns oil, misfiring, and noisy).

Naturally, I'm not too keen on the idea of blowing money on building/rebuilding a 305, but at the same time, the news has come at a bad time, meaning that the funds simply aren't available yet to do a proper 350 build AND the supporting mods (SFC's, better brakes, strengthening the T-5, etc, etc.).

Overall, I basically just have a few questions on what would be the best route to go for now between these two options I had in mind.

#1 - Try to find a cheap 305 TPI in good shape - the benefit here being I can save the TPI to use w/a 350 build later on. (Say what you will about TPI, but it's what I wanna use! , plus it's just a street car/weekend warrior).

or

#2 - Try to find a cheap 350 TBI in good shape, and find a standalone TPI system to use w/it later on - The benefit here having a 350 to work with instead of having to go find one later.

Would a 350 TBI be too much for the stock T-5 to handle? And would it run ok on the TBI exhaust? Or would it just get choked up too much?

Help appreciated!

 

it depends on your funds and expectations/goals

if you look around, and yank the engine yourslef, you can get a SBC rebuilt, including parts and the heads done for $1300-$1500.

You could also consider a reman'd long block

you then would have reliability and peace of mind


if you really want a 350 then you'll be changing the fuel pump to go to tpi as well as the computer

it sounds like you must past emissions so state laws may also need to be considered

and last, buying a used engine is simply that, buying a used engine.

you could well be back to where you are within days/weeks/months having to rebuild that used engine

 

Hmm. Yeah, I realize buying any used engine is a gamble. But would compression testing it before buying one be "good enough" to see what kind of condition it's in? or would the only true way to know be to actually see/hear it run too, or tear it apart?

The main interest in a used motor was being able to get my hands on a TPI system and ECU all together easily. Unfortunately, it seems like the supply of TPI 305's has become scarce around me.

The other issue too, is that as much as I want to get my hands on a rebuilt 350 longblock and TPI, or maybe even a shortblock and top end kit, the car simply needs alot of other supporting mods to handle real power. No SFC's, stock t5, stock disc/drum setup, no posi, etc. What's the point of having all the power if the rest of the car can't handle it, right?

Sounds like my options are to either chance it on a used motor as a cheap solution for now, or absolutely baby the car w/a nice motor in it. Just don't have the funds to do all the mods at once. I want to restore and build/mod this car, but I want to do it right. At the same time, it'd be nice to have a decent running motor in it so I can at least take it out and enjoy it along the way. It's a work in progress

 

part of your issue can't be solved here. Honestly, talk to your folks and understand wants vs needs. If what you need is a vehicle to get you from point A to point B then fixing what you have might just be the most cost effective solution.

if you do not have the wherewithal to repair what you have then you certainly don't for a swap be it used or new.

many threads here and other forums lack the most important piece; a plan and expectations. You must sit down and honestly assess your needs (not wants), look at your funds or available credit, assess your ability or the need to pay someone, the availability of transportation for weeks (possibly longer) while the car is being worked on and then you will know the path to travel.

You aren't at the how to portion yet. I wish you luck and there are many good people here ready willing and able to answer questions once you know which way you are going.

 

Ok, I run a tight budget, and I'm not sure a dollar amount that you have to work with, but on a budget, there is only one small block Chevy that I'd run.

http://sdparts.com/details/gm-goodwr...gines/12530283

The L31 Vortec.

Now if you don't have 2 grand to drop an a new long block, you're in luck. The Vortec (VIN Code R) engine was made in literally thousands of GM trucks from 1996 on up. If you need a reliable getting from A to B engine, this is your best route, in my opinion.

You should be able to get a runner as a "take out" from a wrecking yard for a few hundred bucks. All you need is a long block (block and heads bolted together) and NOT the entire engine. Reason being, all of your front accessory drive will bolt right on from your 305, your flywheel will bolt on, and so will your horrible exhaust manifolds. For everything except the intake manifold, its a straight bolt on. The cam is mild enough that it shouldn't hurt an emissions test for right now, just leave it in. You can change it later when you are hopping the engine up AFTER you have the rest of the car driving as it should.

Now for the intake, you have options. You can buy an aluminum intake for your TBI to just bolt on. A few different companies make them, so there are plenty of options for new ones. There's used ones to be had on Craigslist and eBay, so you can get them second hand too. I would start looking for a used one now, before you even have the engine so that you're ready to go when its time to drop it in.

That's just my budget advice, man, you can take it or leave it. Good luck whatever you do!

 

A vortec set-up was actually kind of what I had in mind for long-term w/this car. The only real issue w/going to a scrapyard for one though, is that based on what I've researched in my area, and how much scrapyards are asking for pullouts, I think I'd be better off getting a rebuilt longblock from a machine shop.

I also want to run TPI, which was where the idea of hunting down a 305 TPI came to mind. Since most people aren't looking for 305's, it might be a good way to get all the TPI stuff for a good price, and hopefully, a better running motor to use temporarily (I've seen whole motors going as cheap as just the TPI setups alone). I know some of you will say "Go HSR!", but I decided on TPI to stay smog legal, and for aesthetic reasons (Not having to cut metal out of the hood for clearance issues, plus I love the look of TPI).

And yes, I do realize I will need an aftermarket vortec intake manifold to use TPI w/vortec heads, but I am ok with this. Unless of course, there are other good, conventional small block head options, but it's my understanding that vortecs are pretty much a great bang for the buck power maker, and more budget friendly than alot of the conventional SBC head options.

I guess these are the last few questions I have before I finalize my engine choice..

- Other than the heads, are the Vortec 350 longblock's internals superior to those found in a 350 TBI?

- Will the rest of my car handle a stock vortec 350 ok if I baby it for the most part? (until other mods). This is the big one to know for me to decide if I want to find a cheap 305 TPI from a yard for now, or if I should just buy a TPI and vortec intake manifold to slap onto a vortec longblock, and be done w/the motor stuff for the time being.

Thanks!

 

Would you happen to have a comparison between the 2 cams?

To the OP, I'd recommend a rebuild of your current engine, and if you really want a tpi setup go with a stealth ram.

 

if you are missfiring you may only need a good tuneup
or ignition repair and there are causes for burning oil
that can be corrected without a rebuild.
How many miles are on the engine and are any plugs
getting oil fouled? Miles on the engine doesn't tell the
whole story though as an engine with decent
maintenance,effective air filter,ETC may go well past
300,000mi wile one that has been boiled dry of coolant
or run without air filter may be in bad shape with only
10,000 mi...

 

Just about EVERYTHING in the Vortec 350 short block is better than everything in the 350 TBI engine.

The block is better because its already machined for the roller cam and roller lifters. Most TBI engines still use a flat tappet cam. The TBI block has the provisions cast into it to be machined for a factory roller setup but the Vortec is already done.

The connecting rods are better. The Vortec engine uses PM rods (powdered metal) like the LT1 has. They are good for 400 HP easily. The TBI uses standard stuff.

If you ever split them apart, I think the differences will amaze you. The block looks to me to be a little "beefier" for lack of a better term, the pistons are quality and so is the crank. By starting with a vortec you are starting with the best factory mass produced stuff that Chevy ever made for the small block chevy. You'll start with a set of roller lifters and PM rods and those will save you some money with your TPI project.

As for the rest of the car handling it, if you leave the stock L31 cam in it, its pretty tame. You won't be making much power over your TBI 305. You'll have all the advantages in place, though, so that when you get your TPI stuff you're a cam swap away from doing well. You can easily just slide an L98 cam in there with your TPI intake and be right there with all the factory 350 cars, ready to go!

If you're on a tight budget, it doesn't make sense to me to start with anything else but a Vortec long block.

 

I don't see anywhere that you've said exactly how much you have to work with right now. That is a crucial thing to know to give a good answer to this.

Personally if you could afford it, I'd do what KrisW says and get a 350 vortec engine. Or even a LT1 engine (I've seen running LT1s in my area for 800-1200ish), the nice thing about an LT1 is as long as it's complete you'll have the TPI on it already. You'll just have to consider that you'd need to get some other stuff for the swap, like a wiring harness adapter unless you want to muck it up and do splicing. I don't recommend splicing as it's ugly as heck and can cause other problems later, but if your on a budget sometimes you have to do what you have to do. I don't know if there are any other large expenses involved in a LT1 swap as I haven't done a lot of research on it yet, but I have a LT1 in an 84 in my back yard and it's got some descent power to it. Your T5 should be able to handle either as long as you don't do any huge clutch dumps and aren't really hard on shifting it all the time. And you don't really need SFCs for a street car / weekend warrior at all. Even a LS1 doesn't put out enough power to need SFCs for a street car. If you were doing some kind of performance driving / autocross or something like that with it then yeah you might need SFCs for a powerful 350, but I doubt you are going to be doing anything on the street that is going to flex the body enough to need them.

My T5 lived through quite a bit of pounding after upgrading to a performance 350 motor that for the past 5 months has been putting out around 275 hp and 305 lbs of torque. It's supposed to be closer to 340 hp and 380+ torque, but I've had some things tuned wrong and a stock 305 intake that has been limiting it's power.

Your mileage may vary, but I doubt a stock model 350 vortec motor is going to be putting out much more than 300 lbs of torque (a LT1 puts out around 325 lbs of torque), and the WC T5 (which you should have in a 91 bird) is rated up to 265. I think those ratings are always a little conservative. At the very least if you take it easy on the clutch, I think it will last you long enough until you can afford to get a T56.

Another option, look at salvage auctions for wrecked 94 to 97 trans ams and camaros with a T56. Most of the time the wrecked cars go for pretty cheap, and there isn't anything wrong with the tranny or motor. So you could then do the entire drive train swapped.

Again though, this all depends on your budget. If your budget is a couple hundred dollars I'd suggest looking into keeping yours running for now because you aren't going to find anything any better for that cheap.

 

I tend to disagree with this statement. Not from a performance or handling standpoint, although it does improve both. I've had more than a handful of 3rd gens and every one of the hardtop models except ONE had mysterious cracks on the roof, at the rear of the side window openings and going out into the roof.

I am convinced that they were caused by the body flexing, since the roof is now part of the frame in the unitized body construction. The only car that got away clean was an 85 Firebird that was a factory Iron Duke 4cylinder car. That car maybe didn't have enough power to stress the chassis? I'm not sure; all the rest of my hardtop cars had the cracks.

SFCs are the first mod to any 3rd gen at my house from now on, barring repairs to get it roadworthy first.

 

Hrm, I don't know. I haven't seen any signs of any kind of damage in either of my camaros without SFCs. But both are T-Top cars, perhaps the hardtops are cracking with the flex since they don't have any room to flex where as with T-Tops they've got a little play?

I was speaking mostly from a performance / handling perspective. Have never given much thought to actual structural damage caused by flexing =/

 

Maybe the t-top cars allow flex, I'm not sure.

I remember reading on here something about t-top cars having extra bracing in the sides of the cars to make up for the roof being missing, structure wise. I bet those extra braces have more to do with it than the roof itself.

The next time you are junkyarding, you should look at the upper rear window hole corners of the roof. I bet you'll see what I mean then. When I get home I plan on taking some pictures of this damage and posting it up in my build thread for my 88 Firebird.

 

Ok, I'm sold. After reading through the replies, I've decided it's Vortec for me! But I still have questions (of course).

- Regardless of whether you use TPI or TBI w/a Vortec longblock, will you need to get a special tune to get everything running properly?

- How bad will the stock TBI exhaust choke up a vortec? I've heard that the main problem is the crappy stock manifolds...

 

If you do anything that is not 100% factory correct, you need a tune to make it perfect. However, there is enough tolerance in the ECM settings that it will run. It will not be perfect but now you get to do some tuning too. You can absolutely do the tuning yourself. If you have mastered how to get through these forums, you can do it!

I really believe that if you get a used, take out, L31 engine and leave the stock cam in it, you'll be fine while you figure out how to burn chips. Start reading in the DIY sections of TBI and all the forums on what to do.

For exhaust, the cheapest thing to do is to go on eBay or the classifieds here (or the wrecking yard) and get some manifolds and y-pipe from a TPI car. Your y-pipe is the worst part of your exhaust and the manifolds are the second worst. Lucky for you, the TPI parts are straight bolt on with no modifications needed.

 

Ok, back in here after a brief abscence!

I had a few more questions. While I still plan to do a nice TPI setup on this car down the road, I haven't been able to find any cheap TPI systems for sale locally. That, and I'm still concerned w/the motor making too much power w/TPI before I can do other things like a better tranny and SFC's and such.

Make no mistake, I'm planning to simply snag up a reman longblock once I can, but I was thinking about just running my TBI on it for now, since I often find the vortec manifolds for them for sale for pretty good prices, and I would think the power output would be tame enough. If I were to do this, is the only real difference between the TBI 305 and 350 setups the fuel injectors?

Also, info on how to tune, or a link to a guide would be awesome! But regardless of what I run on top of the motor, either the TBI or TPI computers would be ok to run w/a stock vortec setup?

 

Im going to buck the trend here... if you're on a budget and you need something to get around in, and you dont have gears, a good trans, or sfc's ,or a posi, or anything...

Go find someone swapping to a 350 from a 87-92 305. They'll probably give it to you for free to get it out of their garage. Compression test it, pull the pan and see how much play is in all of the rod bearings. I say 87-92 because they come with roller cams, which are much more reliable.

I gave away my 305 years ago just to get it gone. Im not the only one.

 

Ok, quick update in here guys.

I'm still in the same spot I was before w/the car. However, in the not too distant future, I should have access to some new funds, and be able to get my hands on another motor.

I know that the rebuilt route will offer more peace of mind, but I'm keeping the option of a low-ish mileage L31 longblock in mind IF I can find one in good shape, and for the right price. However, based on what I can find in my area, rebuilt L31 longblocks seem to be going for about $1300-$1600.

Now here's the question. That's usually w/a core exchange. Will most machine shops accept a 305 as a core exchange, or will I get laughed out the door? . Just need to know, cause if the 305 is useless in that regard, then it's junkyard digging for a good core or low mileage longblock

I'm also planning to do bodywork on this car, hopefully this summer, in which case, funds will also be budgeted in for some SFC's.

 

call me crazy but if you need something to get you from a-b and kind of short on cash why not get a beater car thats good on gas then you can have something to drive and you can hold off on the camaro til you get the money to do everything you wanna do at once just an idea if you can find a good deal on one you might be able to score it get plates insurance and title transfer and still have a little money left over for some gas and you wouldnt have any down time of swapping motors

 

Ok, I'm back to bring this thread back up again, lol. I'm finally getting back into getting some work done on the car. I've done a fair share of the research that I need to, and in the not too distant future, will be looking around for a motor. I've decided the path I'm going is snagging up a good running L05 350 TBI motor, for the following reasons.

- Cheap and easy to find. Salvage yards in my area want too much money for used L31's. L05's pop up pretty often on CL too.

- It'll give the car a little more juice without pushing it to power levels that would be too much for the stock T5/10 bolt/frame to handle (SFC's are early on the "to-do" list)

- I'm going to need to pick up a 350 core to exchange a machine shop for a fresh build later on anyway, so I might as well see if I can't score a decent runner in the process.

Now, I do still have a few questions about the L05 (and vortec heads) before I start looking around. Both swap and modification related.

- Does the L05 use the same ECM as the L03? Will I be able to re-use my own wiring harness/emissions equipment from the L03 and simply swap everything over to the L05? (w/different fuel injectors/any sensors that need changing of course)

- I was told L05's from trucks have flat tappet cams, but L05's from cars (Like the Buick Roadmaster) came w/factory roller cams. I don't plan to do any cam swaps any time immediately but is there any other advantage to roller cams, other than better performance? How much work is it to convert a non roller L05 to roller?

- Speaking of cams, I've read stock vortec heads aren't a big fan of really aggressive cams w/high lift. How much cam is too much?

 

Don't do it; well hopefully you didn't do it already. Its been a while I know.

Keep searching the wrecking yards. Different wrecking yards. I can get 5.7 VIN code "R" engines for 500 bucks in core condition. You want that block instead of an L05 block. I have not seen any L05 that was a roller but I hear rumors. If you can get any 350, 87 and newer that is a roller cam block you'll be okay for what you are trying to do. Its too much money at the machine shop to convert an L05 block to roller but it can be done.

An L98 block or a vortec block is better.

The Vortech heads can't go beyond .480 lift without machining off the valve guides some. Most guys grind them down so that you can run up to .525 lift. Its really cheap to have the machine shop do that so have it done before you run them.

 

I'd go l31 dude. I paid $225 for mine and got to see and hear it run before I paid and the guy pulled it for me and it was complete minus the computer and harness.

 

My 383 is a roller and I bought it primarily because it was suppose to be a crate.Went to reseal it to find it needed bearings...............well thing went astray from there ending up to be a 383.My point is it is a 1995 L31 which is a transitional yr so they came both ways. Flat tappet and roller.Yep my was a flat tappet which I was able to swap a roller into it.To be sure,you should buy a 1996 to 2000 truck 350 to get the roller block.

One regret is I didn't get a LS engine and invest in that.

 

Im not sure about any 1995 L31's... I know they used the same block for some of the late L05's as they used with the L31's... but I dont think the L31 package with teh Vortec heads and roller cam were ever used in an L05 or used before the 1996 model year. However some of the later model L05 blocks had the threads tapped and cam area in the front tapped and so forth for roller block hardware. So if you can verify all the holes are threaded for that stuff, there's nothing wrong with an L05 block and just bolting the right hardware onto it. It's not expensive, but it's still cheaper and easier to find a roller block thats already ready to go.

And I definitely agree that, in this day and age, investing in building ANY gen I sbc isn't necessarily the best idea with the power you can get out of STOCK gen III stuff. But if you're gonna build a gen I engine, starting with a roller block helps a lot. Building a flat tappet engine these days is just foolish.

And for the record you need to look for the holes tapped in he pedestals in the lifter valley, the milled/machined tops of the lifter bores, and the two bolt holes on either side of the cam snout for the roller cam retainer.

 

Yeah-we refuse to build flat tappet engines any longer.Main reason is guys don't believe the cam break-in is continuous through out the life of the engine.We have seen failures many miles after the cam was installed.Tried of customer complaints who don't do it right.Plus the roller profiles are truly that much better.

 

Hey guys, I see this thread is back, lol.

To those wondering, no, I haven't done a swap yet. And I decided against the L05 block. For some reason, I was under the impression that they're roller cam ready, but then confirmed that they need some machine work for it. I heard car L05's (ie, Caprice cop car) came w/a roller in them already, but I see very, very few of them around here.

Once I get a workspace to do the swap (soon), the plan is to snag an L31 set-up. Despite trolling CL and yards lately, used selection is still poor. Rebuildable cores are going for more than I'd save bringing one to the machine shops I've called, and what many yards nearby want for runners basically justifies simply buying a rebuilt longblock IMO.

Only real question I have left at this point is regarding cam lift w/the vortec heads. For now, I'd probably just leave everything stock, but would probably consider something like an LT1 or LT4 cam later on. I heard an LT4's lift specs are right around the limit of the stock vortec lift spec. Is running an LT4 cam on stock heads pushing it? And if I did have them machined for higher lift, will it change anything about how it runs on the stock cam? Would I need to make any tuning changes?

 

the stock heads won't take the lt1 or lt4 cam with its stock springs. You need to upgrade valve springs then your good to go. I just ordered a spring kit (springs, locks, and retaintainers) with some upgraded valve stem seals for $121 shipped to my door. Check out alexsparts.com

 

Once you have the guides cut down and some good springs put in the heads, it will still run perfect with a stock cam.

You really need to do this no matter what cam you are gonna run.

 

Ok, so based on the last two posts, and a bit more of my own research, it sounds like the valve guide/spring job is a must-do upgrade for any vortec head set-up. So I will just have to do that then! Sounds like I have the long-block part of this build pretty much figured out now.

But as usual, I'm still left w/more questions before I start gathering up other parts I need. More specifically, intake choice and hood clearance stuff. Rather just post it here than make a new thread.

The current plan was to run a built-up TBI set-up to feed the motor. However, I'm starting to wonder if the GMPP Vortec intake is too tall for a factory firebird hood to clear? More specifically, a turbo-bulge hood off an early T/A? I put a fair share of work into fixing one up, and ideally, want to fab up a functional scoop setup with it. Plus I love the look. I want to keep the car looking as close as possible to stock on the outside and make it somewhat of a sleeper. No gigantic cowl hoods or 4th gen style ram air hoods for me! .

But yeah, I just need to know if the vortec TBI base will clear the hood before I spend the money on one. Can't seem to find an answer on this from searching it up.

 

I think you should get it and then take it to the machine shop and have them mill it down for you at the TBI mount flange.

 

if tbi is carb setup you can get a shorter intake for ALOT cheaper than gmpp. look up summit for vortec carb intakes. id go with the rpm preformer intake myself( i am actually lol). then get the spring kit i showed you from alexparts( i just got mine today and i am VERY happy with it and well worth the $121 i spent. i got new locks, retainers, springs, and valve steam seals for that price and it was all shipped to my door.

 

Yeah, I saw that spring kit you posted, and have my eye on it for sure. Only problem w/the carb intake and TBI adapter plate approach is that it's going to be a street car, and I have smog legality to deal with where I live. The carb intakes are alot cheaper, yes, but they don't have the EGR provisions. I also have to ask, are you running this set-up now, and does it clear your factory hood? I would think the adapter plate/any spacers would add height too.

From what I can tell, the GMPP Manifold looks similar, but maybe slighly taller/wider where the TBI mounts than the Edelbrock TBI manifolds, which from what I've heard, clear stock hoods just fine.