wammac

Ok well i did some figuring and a mustang gt 4.6l puts out 300 hp and 320lbft Which would be about 65 hp/Liter and 69 ft lb/ Liter.
While the 5.0l tpi(1987) puts out about 190 hp and 295 lbft. Which would be about 38 hp/Liter and 59 lbft/Liter.

Is it possible to make a 305(without boost) make 325 HP and 345 lbft?
This would be the same amount of power/displacement as the GT.

Just wondering its an odd goal of mine but the way i see it if they can make it that efficient why cant i? Or has it been done?

Fast355

iTrader: (2)

VERY EASILY.....With the advent of Vortec heads and aggressive grind roller cams it is vey possible. Honestly the GT is WEAK for a 4.6 liter engine. Chrysler is making more power and torque per liter displacement out of their 4.7 engine in the 2008+ trucks.

You can make the power numbers you are looking for with TBI if you are so inclined.

wammac

Okay I figured. How cheap could it be done? I have a 305 tbi and a 305 tpi but i plan on just using the tpi. are we talking aluminum heads or just standard vortec heads?

Whats the cheapest it could be done for?

musclecar70sfan

iTrader: (1)

300 hp out of a 305? i'd like to do that to my LB9... subscribing!

BluFBdy

iTrader: (1)

you can get good power out of a 305, its really not that hard, you can go with new heads, cam, porting the intake, a full exhaust, a nice rear axle ratio etc.

I started with exhaust, i went with Edelbrock TES headers/ypipe, 3 inch all the way back, really woke it up over the stock alternative, and also a rear axle ratio swap helps ALOT with the torque. Once you get into swapping heads/cam and possibly porting your intake those numbers are easy to hit.

Anything is possible with the right amount of $.... and you can throw that same $ at a 350 and make even higher numbers with the parts listed.

Banksy

Subscribed!

I was interested in doing something like this as well. Looked into Vortec heads from Edlebrok and one thing to remember. If you go vortec style heads and want to keep the TPI then you will need a new TPI base made for the Vortec heads. Otherwise go with a TBI off of a newer vortec motor.

I hope to do my potent 305 vortec/tpi build this next winter (god willing). I get so sick of the 'do a 350' jabbs... I want people to flip when they find out its a 305 smoking them.

BluFBdy

iTrader: (1)

As much as id like to share your enthusiasm its never going to happen. Dollar for dollar the money you put into a 305 could go into a 350 and make completely different numbers, yeah you may take out a stock iroc, but that's it at best. Not trying to be a damper or flame you but that's just unrealistic. The reality is displacment is key, you can only push a build so far and as time has shown the 305 will forever be over shadowed by its 350 counter part. Say for example you've got a 305 pushing 200hp, throw some underdrive pulleys on and you gain 10hp( just an example not accurate numbers). Your neighbor has a 350 and puts the SAME pullies on, guess what...he's stiiiiill faster they just have a better margin on our powerband and numbers

In any case, for those who want to have a good 305 build the key to getting new parts (heads, cam, intake etc) is going to be using parts that compliment each other, go to your local shop and get the numbers, flow test parts, whatever, its all about research and finding the parts that work well together, you can have a brand new set of heads, incredible numbers...match them with a crappy intake and you'll shoot yourself in the foot. My number one piece of advice is RESEARCH before you go click insane on summit and jegs, no sense in throwing down hard earned money on parts that are gonna fight each other

hoogiesngrinder

iTrader: (1)

Vortec heads have a different intake bolt pattern which will not accept the stock TPI base, and the only company that made a compatible base is Scoggins Dickey as far as I know (very pricey). Besides, from what I've read the Vortec chambers are too large to for a 305 and I doubt the valves will clear the smaller dimensions

BluFBdy

iTrader: (1)

I believe edelbrock offers a tpi base, don't wquote me on that tho birdtojag picked up one for his firebird and matched it with a set of edelbrock runners, it will accept the factory runners too tho

hoogiesngrinder

iTrader: (1)

They might have one, but I would NEVER put 350 Vortec heads on a 305.

Edit: Edelbrock makes a hi-flow base, I've never seen one to adapt the TPI to a 96+ Vortec head. Not trying to be rude, and if you have a link PLEASE let me know. I really want to build a 385/TPI/Vortec setup for Fathers car

Banksy

Yup Edelbrok sells a TPI base for Vortec heads.

Banksy

Very true. But for those of us not looking to blow the doors of a viper, and don't want to do a complete engine swap. It's possible, through proper research and planning to build a potent 305.

BluFBdy

iTrader: (1)

yeah i just found it on their site, P/N 3817 but like stated above putting 350 vortecs on a 305 is a dangerous move,

and my build istn gonna blow doors off any vipers, i just went for the 350 because theres more room for improvement later on, and im sick of 305's to be totally honest, but that just me, and if youre gonna be increasing the power output of your 305, im willing to bet its old and a bit tired out, you'll have to pull the entire motor anyway to rebuild it to hold up to the new goodies, so you can just build a seperate motor while still running on the 305 lol thats what sold me, and i got a free L98 block....so i couldnt exactly say no i wanna keep my 305, i just put the money into mine because i didnt have the money for a 350

btw im done jacking this thread lol im startin to feel bad for wammac

hoogiesngrinder

iTrader: (1)

It isn't flow, it will drop compression and the valves will probably not clear the cylinder walls

bronc3buster84

iTrader: (2)

They made a 305 vortec. Kinda hard to find and dont know how good the heads were on them.

hoogiesngrinder

iTrader: (1)

Key words right there. Vorec heads flow really well but are made for the larger bore of a 350. From what I hear the valves need to be filed for the smaller bore. Maybe they would work on a 327 block?

hoogiesngrinder

iTrader: (1)

Shouldn't feel bad, it's better to be told the truth than be led down the wrong road

hoogiesngrinder

iTrader: (1)

Oh, and 305 Vortec heads aren't even close to the 96+ Vortec heads. Should have mentioned that earlier. Sorry :/

Convoy25

iTrader: (3)

"In 99 they did an in depth dyno test on a 305 with over 80k.
Step 1, had dyno readings just headers.
Step 2, added Edelbrock Performer gained 20 hp.
Step 3,changed to 750 holley w/no chg in hp.
Step 4, Added Comp Cams XE262H-10 "Xtreme Energy" gained 53 hp.
Step 5, Chgd heads to World Products 305 S/R Torquer made 300 hp.
Step 6, Changed heads to Vortec GM P/N 12558060. and got 325 HP from a stock 80k 305."

Tilly

there was an article in 93, in the carcraft magazine about the 305/350 tpi engines.
clains that only changing headers, cam, and intake runners you get "just over 300 hp and 380 lbs.-ft torque.I tried to post the article but it wont let me for some reason.

Convoy25

iTrader: (3)

i believe with the right parts it can be done, in the late 60s early 70s the chevy 302 that was used in races was a friggin beast

built91Z28

This topic really gets beat to death on a weely basis. Doing a search will yeild about a million threads that have been started.

The basics of it are....

Yes it is possible.
Yes, you can make more power with a 350, or a 383, or a 400, are a 454... (get the hint, theres always a bigger motor)
F1 engines were making near, or over, 900 horsepower with a 3 litre V10. Anything is possible.

stealth908

iTrader: (2)

327 has a 4 inch bore just like a 350.

Drac0nic

Could make your own too.

https://www.thirdgen.org/forums/engi...take-base.html

1.94/1.5 valved heads can will and do work on a 305. This includes the L31 Vortec heads. Search. This has been covered a few times.

nascar2496

iTrader: (2)

I have a worked up 305. I got the stock motor fresh of a rebuild for $300 with 1000 miles on it. Seeing as how i was in college and had very little money that was all i could afford. So i swaped on some alum l98 heads, bigger cam, new exhaust. It moves to say the least. I ran 14.8 on crap street tires and horrible 60'. Not to mention i recently changed the ignition coil and what a difference that made. Also thats on the stock tune. I believe once i get it tuned properly i dont see why i couldnt be low 14s or high 13s with better tires.

go for it. pm me if you want some more details on my build. I am happy with it for now, once i get a real job and some money im doing the lsx swap.....

89fbirdformula

does anyone on this site know how to search?

its not like this hasnt been discussed 15 times a week for the last 20 years....

Fast355

iTrader: (2)

305 Vortec heads are GREAT heads for a 305......In fact for a 305 they are better than the 350 variant....Anyone that says otherwise doesn't know what they are talking about.

Here is the basics....

1980 C10 Truck...4,500 lbs with driver and passenger

312 CID....Flattop pistons....059 Vortecs with porting a 1.94/1.60....Crane 272H10 cam advanced 4*, GMPP Vortec intake, Q-Jet carb, L30/L31 shorty headers, 2 1/2" duals, 2,600 stalled TH 350, and highway gears with 29.5" tall tires.

The truck SCREAMS up top.

http://www.youtube.com/watch?v=VxJmvWAlIQQ

89fbirdformula

terrible video quality...

But, no offense, that truck accelerates like a turd, doesnt seem impressive at all.

Fast355

iTrader: (2)

Cell phone video will do that. Take note that it wasn't even floored until around 40 mph...And it is no turd. It runs mid 14s with 3.08 gears. Thats 65 mph @ 6,000 in 1st gear and 105 mph @ 6,000 in 2nd.

89fbirdformula

uhm...mid 14s = a turd.

I love how everyone of these "acceleration" videos, nobody ever has it "floored"....

but like i said, mid 14s is nothing impressive..even if it does weigh 4500 pounds.

Fast355

iTrader: (2)

For nothing more than it is....Mid 14s is quick for a daily driver truck with non performance tires, highway gears, a 3spd automatic, and a carbureted 305.

You can listen to the damn movie as bad as the quality is and hear the Q-Jet get slammed on after the truck crosses the intersection.

89fbirdformula

my old K30 sounded the same , even while floored... it wouldnt do the famous quadrabog howl until 60/100 feet or so.

to each his own, but sorry ,it doesnt impress me.

My grand cherokee runs the same numbers with boltons..

Doom86

Cool lets see the video.

89fbirdformula

video of what?

since this is THIRDGEN.org...

heres a video of my formula for the hell of it...

http://www.youtube.com/watch?v=6mUWjTQj2Ps

Fast355

iTrader: (2)

Considering most Trailblazer SS packages with the 400 hp 6.0 LS2 barely break into the 13s in STOCK form, mid 14s are fairly impressive for a 305 in a truck with similar weight. The SS has MUCH better gearing as well.

I bet the dual jet carbed 130 hp LE3 305 and 3spd stick NEW in 1980 would have struggled to break a 20 second 1/4 mile and 15 second 0-60 run.

Its all what you use for a comparison.

T/A IN PA

Just put a blower on it.

bluers91

A 305 running mid 14s is impressive if you ask me and there aren't too many of them out there. It would be even more impressive in a 3400# thirdgen.

Fast355

iTrader: (2)

It would also be more impressive with a 700r4 and 3.73s, even in the same truck. Consider that was the factory setup for many of the L69 cars.

Doom86

Yea it is impressive you have a mismatched 1st/rear/motor it would probably run nasty in a 3rd gen with a decent rear and trans. It's certainly a 300+hp long block I think the TPI on there that you dyno'd before showed that.

InjectorsPlus

iTrader: (1)

Excellent post.

Fast355

iTrader: (2)

Having a MATCHED SETUP is IMPORTANT if you want to actually get down the track quickly.

Certainly not the first mis-matched setup I have done....This setup is practically identical save the 125 lbs of rolling mass I saved by switching out 32" tall 20s to 17" wheels with 26" tall drag radials (dropping my effective gearing from 3.55 to 4.37!!). I also took out an extra 100 lbs by removing the back seat. The weather was a little cooler. The result, I picked up 7 tenths in the 1/8!!! Thats right, I have been playing with more modern engines lately. I still have the van though, building a 4L80E and a 8.5" 10 bolt with 4.56 gears for it as we speak, then will spray it 125 hp.

9.66

http://www.youtube.com/watch?v=vOKiimp8WwA

8.95

http://www.youtube.com/watch?v=6OjA5nq-BjQ

Convoy25

iTrader: (3)

in the end if i was going to build up a 305, i'd do it in a way that i could either use parts for a bigger engine and/or sell them. that being said i'd do the build that i mentioned earlier and slap a supercharger on it

mlynch001

Yes, It can be done! And there ARE good, affordable VORTEC chamber heads with old style intake flanges that can you can bolt a TPI base directly to. EQ makes these heads in 305 Chamber sizes. The problem is that the TPI base will not always cover the intake ports without welding and porting the manifold base. How do I know, you ask? I BUILT ONE! Is it Easy? NO! IS it Cheap? NO! Is It worth it? Yes, If you want to do something that no one else is doing! I can give more details if you like.

Ozz1967

iTrader: (4)

World performance even sells a set of 305 Torquer heads that they say are 30hp over stock if not more. Just throwing them out there as an option because you don't need to change your intake with them.

86Z28beast

I have a built 305 in my car. I would'nt doubt that I am close to the 300whp range. Don't know yet havn't had it dyno'd. forged rods,pistons, 10:5:1 comp, Ported stock 305 heads.2.02/1.60 valves. Doesn't run too bad. Need a better intake and exhaust system though. Tuned running a tpi setup.

Doom86

I don't know I have never heard a single good thing about those heads from someone who used them. Even the flow testing looks bad with them. Maybe someone with good results can correct me but I've never read a good review.

Chevy8588

iTrader: (1)

I have a 305 TPI in my car, and it keeps up with the my girlfriend's 70 LT1 in her 84.

88 roller block
87 MAF TPI
9.5:1 comp
L03 heads
94 LT1 Cam
95 LT1 24# injectors
Ported plenum
descreend MAF and modded air box
9* BTDC timing advance
1 5/8" headers into 3 inch system
T-5 5speed
3.42 rear gear

It runs like a raped ape on a factory tune, new heads, full port and polish, and tune coming this winter