whats up? i am gonna rebuild my 1992 305 tpi for a wild daily driver, spare me the "get a 350" crap cause i'm gonna build a 6 speed iroc for that.
first of all i am gonna use a stock rear end with 3.73 gears.
i have a 700r4 with a trans go stage 2 shift kit.i have t-tops so i am gonna use a strut tower brace and sub frame connecters.
i would love to see 300hp at the rear wheels from a naturaly aspirated motor. this is my first project and would love any advice anyone can give.

 

Im just gonna say what everybody else is thinking. If youre going to rebuild the motor, dont put a 305 back in it. I thought about doing that with my car and it would have ended up costing more to do a 305 than it would have to put a decent 350 in it.

 

so you're building 2 cars?

the reason everyone says ditch the 305, is because they are crap and not worth the money since the 350 will cost less and you get more power.. that being said

300rwhp from a N/A 305

umm.. riiiight.. you'd spend sooo much more money than you normally would on a 350 to get 300hp..

people say ditch the 305 cause they have probably tried to build a 305 and it didnt work out.. i would take their advice if i were you. if you used the you would find pages and pages and pages of this discussion on why you would be better off with a larger ci engine..

BUUUUT

as far as what is going to give you the power.. the heads and cam combo is where it is at.. spend most your money there, then free up the restrictive parts of the TPI, namely the runners, manifold and headers, and need i say, tuning tuning tuning.. this should put you on your path..

 

I'm not to sure of what the HP level would be, but I would try a set of vortec heads, as they are cheap, good, and don't have too large valves, so you wont be shrouding the intake flow.

The heads you have is your number 1 power limiter. Get something else.

Second I would find a fitting cam, here's where the big differences are, so be sure to pick the right one..

Then headers, hooker 2055 is a very popular setup, and people are happy with the gains they see. After that an exhaust that don't restrict like the stock do.

For intake, you could use an Edelbrock performer, or performer rpm, or performer rpm airgap.
They make power in that order. Just saw you had tpi...LOL Easiest thing to do would be to swap to an Lt1 intake, and keep the electronics and whatnot. Get an LT1 fuel rail and intake. Here's a good link on that setup: www.lt1intake.com

I feel that 300 hp is a high goal, especially talking rear wheels, it's probably not going to happen. But on the flywhell, it will.

If you don't spend any money on the shortblock, you will be fine. The day the shortblock needs some work to it, swap in a 350 with the setup you have built, and you will have even more power. No need to make that 305 go to waste, just use it with boltons, and when it goes, let it go.

 

musicmanz28, i suggest you do as KiLLJ0Y said, do a search. you will find that many people build 305s and have great luck. many people feel that building a 305 is not cost effective, but in reality it all depends on wether you actually have a 350 to build, and if so how much does it need. tilstad was correct in saying if the short block needs much work it is not cost effective. i rebuilt my 305 because the 350 i had around here needed pistons, lots of machine work, and a set of heads, therefore it was cheaper to do my 305 instead because all the 305 needed was freshened. there are many reasons to build or not build a 305 and they have been covered at length on here numerous times.

300 HP at the wheels is gettin up there, but it can be done i think. many of us have in the neighborhood of 300 at the flywheel (i think i am at about 270 or so) because all it takes is a cam, decent heads, and a good exhaust to get there. to get 300 at the wheels you will need about 340-360 at the flywheel. that will require a dang good set of ported heads (aluminum L98s or Vortecs) a balanced bottom end, and probably an LT1 intake as was stated earlier. a TPI intake would make more torque and midrange power, but would not match the LT1 intake in peak power. depends on your driving, but i would keep the TPI, i feel that it would make a stronger car on the street than the LT1 intake will. you will obviously need a good exhaust and your cam selection should match your intake selection. a 305 to make this kind of power will cost about as much as a strong 350. unless you just want to be unique, go with big displacement. but i totally respect the urge to be unique, and wish you luck in your 305 project, keep me posted on how it goes. personally i am kind of a fan of 305s because everyone hates them, i have won alot of money from the mustang boys with mine

 

Anything is possible, and this could be a nice buildup. Just keep in mind that theshortblock is what you don't want to spend money on.

If it was me, a re-ring kit, perhaps with new bearings would be as far as I would go on a 305 shortblock. If you need more than that, a 350 will be your best bet. If you want a bit more umph, get some squeeze with a 150 hp N2O kit.

Even a 4.3 or the "3/4 350" can make 300 hp, flywheel that is.

Check it out: http://hotrod.com/techarticles/engin...v6/index1.html

 

I am gonna be different cause i like my 305, i understand the draw backs and i don't care. My 89 iroc will be my power house pony kiler. my 92 z is gonna be my daily driver (weather permitting) I found world products makes a s/r 305 tourqer head and i am gonna buy a set and have them pocket ported, accel makes a tpi base manifold and runners that i like the looks of. With this car im going for a more streetable car that looks like a well maintained stocker. With the exeption of the head pounding flowmaster exhaust sound that does for me every time.
I'm not sure what cam im gonna use but i'll ask around and see whats the best set up. I have alot more plans for my baby blue that i will post later, until then...
p.s. thanx for all of the info.

 

Jsut remember, your limited on valve size, this is the main drawback to the 305, short of it's lesser displacement, go to big on the valves, and they will be shrouded by the cylindr wall. That's why I reccomended the stock vortecs, but then again, they might not fit your intake.

 

accel's base is made by Edelbrock and restamped.. all the TPI manifolds including TPIS, SDPC, Accel are all Edelbrock made..

save yourself 138$ and buy the edelbrock base for 379.. not 517. you're paying for the name of accel.. search if you dont beleive me.

those SR torq's are not much better than stock.. hence the "SR"=stock replacement..

do some more searches and you'll see what i mean.

 

Those heads are most likly an 081 head casting, if he does have an LB9. If they are an 081 casting they can be ported out to flow more than the fabled Vortecs you speak of. It would cost $50-300 to port the 081s depending on the resultls he wants. I am in the middle of a 416 port for my 305 right now. And yes, I have 350s/383s and my sets of Trick flow heads and others.

 

SRs VS stock heads there is a 22 cfm difference. Ported the 081s or 416s beat the SRs.

 

Yeah, I was thinking he had the TBI when I wrote that...

 

That is what I said when I built my first 305. I was excited because I was going to do something no one else wanted to do. Build a hot 305. After it was all said and done, I was right. I was different. My car stood out from all the other 350 cars. Well, it stood behind them . Don't get me wrong, I could hold my own with rustangs and *ice, but I couldn't even keep up with my buddy's stock formula 350. Forget about forth gens. The bad thing is that motor cost more to build than my 350 did. I couldn't believe it. Well, it was a timely and expensive lesson. If you are tring to make 300hp, why start small. A stock 350 is going to get you to 300hp alot cheaper and easier than a 305 will. I'm sure you aren't going to change your mind, but I feel better now. Good luck with your projects.
FBird

 

jeez u guys are relentless... what i am prolly gonna do now is rebuild my 305 with a few performance parts and then port my heads and put a supercharger on, its a vortech and its on its way.( got it dirt cheap from a relative.) i will get the power i would like for now. I think i will start looking for an 89 iroc-z with a factory 5 speed. like i said, t56, and a built 350 or 383. havent decided on what i AM gonna do with the iroc.

 

I just heard about a 335 stroker kit for 305's . superchevy did a project car with it. how about that?

 

Quit asking for permission and build what you want! A supercharged 335 sounds pretty good. Go for it and let us know how it works out.
FBird

 

If you want to spend way too much money for power, tune a honda. The point of chevys is bang for the buck. It doesn't make sense to spend 600 dollars + machining costs on a stroker kit for a 305, when you can get a bore kit for less than 100 dollars that gives you 355ci.

 

"Tuned port 335" is the only one that I know of that has a 305 stroker on here. I was real close to ordering it, than I woke up when I looked at what I could do with a 350 or 400 for the same amount. I had a 355 HSR blah, blah, blah, I drove it until it ate the rod and main bearings. So I put the 305 TPI back in. Sure it has the 416 ported heads, ported/siamesed TPI, 25 lb hr injectors, Mega Squirt, and lots of other stuff. But it isn't even as much fun to just sit there and rev it up. 305's are fun to drive, but for power, 350's are better. A 305 supercharged is almost the only good route though.

 

I understand what you are saying, but for that $100 your just gonna get a worn out 350 block and internals. You will still have to rebuild it (unless your are OK with keeping the stock internals). Granted, it will be a better base to start from.

I'd say $100 for a 350 block, then another $500 or so for a decent bottom end, then add up machine shop costs...

 

Wanna race?

<-- stock heads, rockers, base/plenum/runners/tb, injectors, suspension, hypercrap chip, 2.73s...


Heh, just kiddin

 

I'll race you.
I just had to put the old 305 (or is it new now) back in.