first off i know that switching it out for a 350 is the right way to go but i want to keep the car stockish, but i do want to do the 305 up , SO what would you guys suggest would be the best places to spend $$$ and get the most ... the car has 58,000 on it.. im going to take the heads off as i think the valve seals are going.. so from there what should i do??? thanks kevin

There is a thread on the FAQ forum about the differences between 305 engines and performance upgrades for the 305. Start by looking over the information in there.

The L69 had one of the best factory exhausts for 3rd gens, but it can be improved. If you want to keep the stock exhaust manifolds, get an aftermarket direct-fit high-flow cat and aftermarket cat-back.

thanks , i did do a search but didnt come up with much .. i'll look more..

since your taking off the heads...replace them.

S/R torquer heads are good for 305. They have larger valves.
Add 1.6 rockers, headers and full exhaust.

im just looking at the thread for the exhaust , the new heads are a great idea but more than i can spend right now.. and i now know i can replace the valve seats without removing the heads..

you dont even have to take the heads off to do the valveseals

just an air compressor

get some z28 springs off ebay and some rollertip 1.6 rockers

get a better intake manifold and some headers with a 3inch ex

if you dont have an electric fan get one

curve kit in the dissy

shift kit in tranny

subframe connectors-oh that should have been first

No need to replace the heads, they are actually quite good for a 305. Start with headers and exhaust, then I'd suggest changing the intake manifold... RPM Qjet would be a good choice. You can get all the benefits of the good RPM design, but still use the stock CC Carb you have now.

interesting topic.
I will watch this one for suggestions.
I like the idea of not removing the heads for the valve stem seals.
That's cool. I may need to be doing that at some point.

just take the airchuck out of one of your airtools and put it in the sparkplug hole-easy as pie

connect the airhose to the chuck and then take a hammer and hit the tops of the valves- with the rocker arms off for sure

dont be affraid to give them a good solid smack because the springs will dampin the blow

get a spring compessor and a magnet and get to work

Not exactly. You can replace the valve stem seals without removing the heads, but replacing the valve seats requires removing the heads.

i was thinking about doing the intake even just for looks.. i heard the manafolds are good on the L69, now i have called around for dual exhaust and everyone seems to think it cant be done.. so im working on it..

With a stock cam, an intake upgrade won't do much for you. The L69 and LG4 intakes were the same thing, by the way.

Dual exhaust is possible but doesn't provide any benefit to compensate for all the problems it causes (like reduced ground clearance). That doesn't exactly fit with your "keep the car stockish" goal, either.

Since you did say "keep the car stockish", I didn't suggest headers. If you aren't that concerned with keeping it looking stock, headers should be the very first thing you put on.

If you don't want to pull the heads and don't mind opening the hood and letting people see "hot rod parts", then the order is simple: Headers; high-flow aftermarket cat; 3" aftermarket cat-back; cam. Somewhere in there is subframe connectors, perhaps even before headers.

wow thats what i was looking for five7kid. i had no idea about the subframe connectors though..week spot in the car i take it.. and for the exhaust i will do the high flow cat and cat back .. the car has a flowmaster on it now..and add some nice tail pipes.. and i guess im gonna screw the stock look.. i just wont do anything i cant undo.. lets be honest i would have caved on the stock look sooner or later.. guess sooner is more fun..

I've always done that smacking part with a larger sized socket over the valve spring. Keeps the little clips from disappearing.
I get the idea about the internal pressure. I've never thought to do it like that.
Couldn't you theoretically do it on the compression stroke or is that not sufficient enough pressure?
Just a thought.

There are a few things you can do to make more power - all are bolt ons.

Exhaust - get headers, a 3" cat, and a 3" cat back (L98 cat back)

Intake - Edelbrock Performer EGR is a direct bolt on

K&N air filter, block off heat risers

Underdrive pulleys

Buy an A/F gauge and tune the car using hangars and rods



Way too easy

Don't mean to hi jack a thread, but most of us started out the same way you did. If you have good mechanical skills I would recommend a mild cam swap. I used the 256 Lunati Voodoo. It made good power and low end torque with good vacuum. Would definately wake up your 305 and sounds stock to boot. Nobody will even know! That's the way I like it.

you are right about the socket on the retainer

yes use the air preasure

well i have a direction,, my neighbour just happens to be a part of an engine building family and IHRA team, so hes gonna give me a hand(i helped him with his home theater) so hes gonna get me a set of heads, im gonna do a cam, intake, and gear drive, and his brother in law is gonna give me a hand with the exhaust... im a happy guy right now.. now if the winter could just be over...

make sure the heads are 58cc
and the cam works for your car
Don't do a gear drive

Gear drive is a waste. They make noise and cause real problems. Don't do it.

If anyone suggests replacing the stock carb, don't listen to them. Unless you're building a car for track-only use, the stock carb is the one to run.

Keep the cam computer compatible - there are plenty of them out there that will make good power with the stock computer carb and maintain driveability.

You aren't going to be building the fastest car on the street, so keep it reasonable.

ok thanks for the advise, why not the gear drive though? i had one in my 84 cutlass with the chevy 305 and i liked it .. now mind ya i only had it 6 months before it was stolen, what are the problems with them i thought they were the best option, ya i will keep the stock carb.. what im REALLY after isn't to have high power a little more cant hurt though or race the car.. i JUST want it to sound like it.., i have my sportbike for doing stupid things, the Z28 i just want to cruise... and sound good doing it , again .. i appreciate the advise .. that way i just do it once..

Other than making noise, they mess with the knock sensor.

I don't even bother getting that fancy. I just take a length of clean 1/4 inch nylon rope and thread it into the spark plug hole. Keep pushing it in until no more will fit. The rope will hold up your valves.