Austin90RS

For those of us with the dreaded lO3 TBI/H.O or even the LB9 TPI 305 that want some more power for there ride on a budget...THERES A WAY WITHOUT SWAPPING!!

After having the same dilemma with my 1990 RS with a carb swapped TBI 305, I couldn't decide whether to go off what most SBC enthusiast's think of the 305( trash it for a 350), or agree with the handful of optimists that have ACTAULLY touched there 305's, I figured id see what potential mine had to offer.

GM designed the lo3's(or any 305 in general) to be economical little v8's with minimum power to offer

Heres a list of Go Fast parts I recommend to give your 305 some *****:

• Basics-limitations, flow, weight,timing
• Evap delete, Chips, ECM delete(600-650cfm carb swap )
• a/c delete
• 3" exhaust w/cat delete or high flow performance cat
• 65K HEI Distributor w/8-10.5 mm plug wires
• Aluminum dual plane edelbroke/Holley Intake man.
• Internals/performance parts-Cam, Headers ,head work, gear drive/double roller chain
• Jegs 200105 Hydraulic Flat Tappet*82-89 I believe are flat tappets with some exceptions, Check to see what your motor has! LT1 and LT4 cam swaps are popular swap for roller!*
• headman/summit headers(I got summit's tubes, perfect fit!)*matching down pipe will be needed, unless you attempt duals!*
• 1.6 roller rockers w/+.100'' - 7.900" Length pushrods
• Gear drive or double roller chain(I went with gear drive, more precise in my opinion!)

Following upgrades could get you roughly 280-340HP for under 500$ depending on cam and other factors with your build

I intentionally didn't add bottom end parts or stalls due to following upgrades can be done with motor in the car.theres also more to do with heads(worst part about 305's along with exhaust man's.)
following this list should make that 305 of yours a pretty mean street machine and sure to turn heads.

Anything I missed feel free to share!!!

vetteoz

iTrader: (13)

Unless you got dyno proof I would say you are dreaming if you think you can pick up 100Hp over stock on a 305 for that amount

These 305 perf builds did but it required some good aftermarket heads to do so

http://www.superchevy.com/technical/...d/viewall.html
http://www.popularhotrodding.com/tec...d/viewall.html

If you buy a new cam with the required lift , you don't need 1.6 rockers

Austin90RS

Im "roughly" going off my current build and similar builds ive seen with almost exact mods expect swapped heads, motor dynoed 400HP

Also any bigger of a cam id need a bigger stall and bigger gears in the back and vacuum canister for brakes, Hence why the list is for a low budget build without removing the motor

vetteoz

iTrader: (13)

Did you read the link I posted ?
360Hp with TFS heads and a 750DP

Jeffs82TA

iTrader: (1)

Well if you think you can get 280-340hp out of a 305 for 500 bucks I will buy everyone of them.

I will say I made my 97 3.8 camaro get a extra 85hp and 100ft lbs tq. for 1,000.00 .... haha just bought a donor z28 and put it's LT1 in my camaro.

sorry if a lt1 can barely make that a 305 won't.

sofakingdom

iTrader: (1)

Go ahead, tell em what they want to hear.

After all, it's THEIR money, not yours.

Austin90RS

like I said theres different factors, if you go to a carb from tbi, theres 400$ alone for a holley 4150... mine cost me about 800$ in change, 390$ of which went toward a better carb then I originally had. you could very well spend thousands of dollars on the build I mentioned depending on what you get.

Btw im sure parts arnt nearly as cheap for those 3800 series 2 as they are for a sbc ahah, and a LT1 swap would only make sense in that situation.

Austin90RS

I did, im sure im no where near 360 with stock heads and 600DP,all depends on what you get and your budget

vetteoz

iTrader: (13)

So saying that ,
where did your " could get you roughly 280-340HP for under 500$ " statement come from

bestracing

I had a lot of stuff sitting around my garage for my ECM controlled to Non-ECM controlled LG4 conversion and it still will run you some money.

My Crane cam & Lifters cost $100
Got a used manifold RPM for $25
Had a Holley carb already, rebuilt kit $35
Intake Gasket $15
Timing cover gaskets $5
rocker cover gaskets $15
Timing chain $20
HEI Cap/rotor/wires $80

Just that runs under $300 bucks and that was some of the cheaper priced stuff.

I didn't add the cam bolts, cam bolt retainer plate, fuel lines, hose clamps, antifreeze, spark plugs, carb tuning kit, air cleaner/filter and there are some smaller stuff in there as well.

Drkhrse89

iTrader: (1)

I'm glad you listed this stuff. These are the items that people never think about when doing their budget. If you are throwing in a cam you have to drain the coolant. To refill it is not free. I actually left these items off of my list, only because I wanted the wife to think I was spending less, but know that I am going to be spending another $100+ in fluids, etc. to get it finished.

TxTtopZ

Another expert with like 10 posts and minimal time doing the research thats been done on this board and other places.
Im not trying to be an ***, I appreciate your enthusiasm and all but trying to throw a 305 sales pitch in a place like this is selling ice cubes to eskimos. How about telling us you have invented a 18 degree SBC head with a 58cc chamber that measures 3.736" across and repositions the valves to accept 2.02/1.60" inches. Has breakthrough anti-shrouding technology and its compatible with early and later style SBC intake patters. Oh yeah, theyre also aluminum.

Please do some searching and then bring some numbers. Bench racing the 305 is borderlining a banned topic.

hillntx

This thread comes back to that age old 305 boat anchor debate. The reality is that any performance upgrade that works on a 350 also works on a 305. There are after market heads available through World Products (SR Torquer 305) and some others. Changing the intake, exhaust, cam, and heads will give you more power. Chevy High Performance did a series on it "My Generation Camaro" with good results in the low 300 range. So if you're on a budget as most young guys are, you can slowly buildup your 305 over time and get a respectable level of performance and have a car that's more fun to drive and the sense of satisfaction that goes with it.

However, as is always said in these threads: If you make the same changes to a 350 you get more power for the same money. With the bigger displacement the power potential is greater, you have more component options available, and it bolts up to everything already in your 305 equipped car. You CAN build your old 305 for more power, but for a couple hundred more you can build someone elses old 350. The choice is yours.

I'm not an expert and don't have a billion posts, but I have had my 1985 Camaro since the summer of 1986 and seen this debate many times.

InfernalVortex

iTrader: (4)

You can spend built 350 money on a slow lowish compression 305 with a bad induction system if you want. Not really my cup of tea, but to each his own.

bestracing

I'm good friends with an Eskimo and in order to accomplish this (above) you just need him to live in a warmer climate. (Ky) I know, I've been there, done that.

TxTtopZ

Sucks... Technology and the latest additions from manufacturers has made the 305 a relic. I love em anyway.

bestracing

Same thing can be said with any Gen I SBC motor really since the intro of the Gen III LSx motors. But I still love my "Old School" motors as well.

I have actually started on rebuilding a 1987 350 block for my 86. I've torn the motor down and inspected the block, crank, rods and pistons but my plans are on hold for now since I have to have neck surgery soon. Besides it being a "Pain in the Neck" I have medical bills to contend with now as well.

TxTtopZ

Which makes me think SB2

cosmick

And here the title made me think this was about nitrous.

89rs454

i have an 60000 mile Lo3 setting in the shop, convince me why i shouldn't put it on my lawn mower?

sofakingdom

iTrader: (1)

1. Use too much gas.
2. Leave deep wheel ruts.
3. Bog down in thick grass; a 454 will go through it faster.
4. Won't sound good no matter what cam you put in it.
5. Heavy and hard to push.
6. Hard to find the right adapter for the blade.

rusty vango

psssst, never say "305" on here. sofa will smite you heartily!!!

Formula 305

InfernalVortex

iTrader: (4)

yeah I dont think the 305 guys are going far enough. Im going to put AFR heads and forged rotating assemblies, shaft rockers, and huge roller cams into a 265 sbc. If less is more then the 265 should whoop up on all the 305's around!

Johnny Blaze

iTrader: (15)

So which is it?

rusty vango

how about sleeving a 350 four bolt block to 3.766.and then all that forged ,balanced rotating assy. and some torker SR heads? i mean if youre bent on a 305 make it one hell of a mouse motor

robertfrank

iTrader: (27)

You know, I myself used to be on the "build the 305" bandwagon for years. I probably had one of the quickest 305 TBI cars on this board and from personal experience I really wish I hadn't wasted my time. Sure, my car was pretty damn quick for a 305. It was an honest mid to low 13 second car without a doubt but now that I've done MINIMAL mods to my 91 350 TPI car its just as fast for far less money and time. I'm building a Single Plane efi ebl controlled LT383 for my racecar and I wish I would've done it years ago.

89rs454

What happened to your 305?

robertfrank

iTrader: (27)

I parted it out to help finish paying my 383 shortblock off. It ran like a champ and in the 9 YEARS of me beating the hell out of it it never once gave me any trouble. It was actually sad to see it get loaded up on a truck for its next owner lol.

89rs454

I bet them 305s are stout motors.

Johnny Blaze

iTrader: (15)

Can you improve the performance of a 305?
Of course!

Will the same parts and cash invested into a 350 make more power?

Everytime!

SilverChicken

iTrader: (1)

One way to consider building your 305, which is exactly the route I'm taking, is to use parts that will be equally at home on your 350 build. Headers, intake manifold, rocker arms, distributor , etc. can be reused. Things like cam and carb won't be optimal for the next step up motor but flat tappet cams are cheap and carbs can be sold for a small loss to the next guy in line. That's how I'm slowly getting ready for my 406 SBC. Why don't I just go ahead and put in the 406? Needs many thousands of dollars before it is ready to run and decomputerizing the car, getting the th350 swap ready, buying exhaust, heads, valvetrain, rebuilding the rearend and getting a good differential, etc, etc is one way to big of a step when I can approach the 305 in stages that lead to a much smaller step into the 406.

Johnny Blaze

iTrader: (15)

^ good thinking.