i have a 89 iroc 305tpi----

i don't want to replace the car at this piont-
-has anybody ever done this and if so with what rockers
-what are the stock ratio for my current rocker arms.

i'm looking at 1.52 - 3/8" Comp Cams 87-Up SBC Magnum Roller Tip Rocker Arms
the are like 200..
what otrher parts will i need when replaciong these

 

Those rockers are an excellent choice. I plan on adding a set to go with my Crane Cam, but I suggest you get a better than stock cam to go with them to make a good noticable differance.

I am using the same COmp Cams magnums 1.52 ratio on my Z24


After a year they hold strong and car produces 225fwhp over the 140hp stock

Hopefully I can see some big improvements in my 305 this summer. I am not adding to much, cuase I have a 400 sb I'm building but the CAM and Rockers and some porting and head work ougth to be nice for the next year.

 

What other mods to you have to your front driver to get 225 fwhp out of it?

 

9.3:1 compression from stock 8.1

bored .030

JE .75MM Hypertechtic Pistons

Crane Cams Chrome Moly Pushrods

Manley Forged Aluminum Rods

1.52 Ratio Rocker Arms

Crane Cams PowerMax

Adv. Duration: 264º/274º

Gross Lift: .423''/.423''



Stage II Jet Chip

Aluminum Heads 3-angle valve job

Hypertech 160 degree thermostat

Perma-Cool Engine Oil Cooler

MSD 8.8mm Sprial Core Wires

Champion Racing Spark Plugs

Accel DIS SuperCoil Packs

FDP 62mm Throttle Body

Ported Intake & Plenum

Shifter Improver Kit

305 19lb injectors vs stock 15lb

Hi Flow Intank fuel pump

K&N Air Filter

Cold Air Intake

150hp EFI NOS Kit

Magna Flow 2 1/2 exhuast with 3in outs

Exhuast, off road pipe, 2 1/2inch pipe

Thats about it.

 

Can't wait till I am done building my 427 for the IROC

 

You've got a fwd iroc?

 

LOL. No, those mods are on his Z24!

 

no thatz his Z24 which is front wheel drive

and i'm looking at the gm ram jet cam, i don't ave alot of cash to spend, plus the am i only 135. i'm also looking at the LT4 in a future rebiuld

 

The LT4 cam isn't all its cracked up to be, its over hyped on this board. Really the duration and lift is no greater than some Comp, Crane or Lunati Cams you can order.

You've got a 305 with breathing problems so don't go to radical.

Something that gives you good torque and horsepower low to mid would be good for a 305.

With those 1.6 ratio rockers a ported plenum, high flow runners, and good free flowing exhuast, and if you have the money or time, porting your heads and vavle job. You chould see a good increase.

I think I saw you have a 5-speed which puts you in the higher HP range for the 305 to begin with. So taking it up some shouldn't be all that difficult.