well i just bought an 87 IROC, with a 305 TPI....the car has 150k miles on it and still runs like a clock.....i already have a set of headers im going to put on it, and i plan on replacing the whole exhaust. im also putting in 373 gears. hmmmm...im also puttin gin a 52mm throttle body on it, fuel presure regulator, fuel rails, and new injectors. when thats all said in done, i want to put a different cam in it....now i know pretty much all needed to know about the stuff im already putting in it, BUT, im not too sure about the cam....

with all those upgrades im not going to dive into the pistons just yet, i dont have roller rockers in there, but i was thinking about changing that over, if i did put roller rockers in it, how much of a pain would it be to change that over.

now to my original question, what cam do you guys think i should throw in there, with those components and the stock bottom, also keep in mind this is my daily driver so i cant throw in a massive cam just yet.

thanks a bunch,

perry

 

The first thing I'd do is fix that incessant ticking sound. ("It runs like a clock...")

Then, before diving in head-first to change everything, drive the car a while, learn it's tendencies, change all the fluids and filters, perform all the necessary maintenance, and see if it's worth the expenditures you plan to make. You may find that the transmission is a little sloppy, and need to fix that before routing any more power through it. Ditto the rear axle. If the car has no reliable brakes, loose steering, cracked fraime rails, won't track straight down the road, you may need to divert some of your energies toward repairing that rather than changing things that already work.

Once you have a feel for the car and know that the major systems are reliable, you can devise a logical plan to do whatever improvements you may want that fit within an overall picture of what you are trying to achieve.

Obviously, the cam would be the first thing to go. With that, you should install better springs, better rockers, and better rocker studs.

Money spent on a larger throttle body for a 305 is essentially wasted, since GM has proven that the 48mm TB can support over 500 HP on the RamJet 502. An engine about 2/3 that size certainly won't need more air than that. If you're worried about intake air flow, fix the areas in the plenum behind the throttle body and where the runners attach. They are the real restrictions. Then clean up the flow from your air cleaner housing. Remember that the '87 has a "garbage can" air cleaner, so any extra holes need to be cut on the INSIDE, not the outside of the housing.

Instead of new injectors, have the old ones cleaned and flow matched. The Bosch/Rochester injectors that came with that engine are very reliable. And why would you install new fuel rails? Are the old ones damaged?

At that point, with a reliable ignition, clean injectors, and a decent cam setup, you'll be getting about all you can without some serious head work or replacement.

An AFPR is not a bad choice if there is something wrong with the original, but if the original is working fine, there is no real gain from changing it (been there - done that). You'd be better off by far to spend the money intended for an AFPR on a PROM writer. You'll get a lot more out of a tuned PROM that you ever would from an AFPR. Take some spare hours and teach yourself how to reprogram the PROMs to do exactly what you want. You might be amazed at what even a stock setup can do with only a properly programmed ECM.

 

when i said the car is running like a clock i ment that it is running as should, everything is in tune and running great. the engine has no knocks or anything in it, i can hear the injectors pulsating thats how well the engine is running.

second, to all the things that i wanted to change about the fuel system, the new fuel rails, no there is nothing wrong with them but i already have a brand new set, i figure new is better than old. all the stuff i wanted to put on this car i was hoping to get a good gain off of the 305 and still have a little bit of a gain when i put the 350 on, i wanted to buy a 350 but i dont have the money for it, so im going to start building a good top end on my 305 to later just throw on to a 350 short block, thats why i have so many upgrades.

now i see that you said the cam should be the first thing to do, i understand that but i dont know much about the cam, what would be a good cam to throw into a 305 by the way, Vortec Heads are going to be put on in a few months, like i said i want to put on upgrades on my 305 that would be also an upgrade to the 350 since i am going to just take stuff off the 305 and throw on there....long tube runners are on the way, and bigger injectors to go on the 350,

so like i said, all this stuff is going to be used on a bigger engine, though, im still not sure about the cam, what numbers should i be looking at, as in how big the cam is

thanks

perry

 

i thought 87+ had roller **** in it?

 

just a roller cam and lifters, not rockers.