what can i add to increase hp to my 87 iroc it has a 305, headers, new excust and 600 carb

 

It is a summet 600 dblpump carb if that helps more

 

There are several ways. Your question is a little on the broad side. You probably need to qualify it by telling us your goals and budget. Your mechanical ability certainly has an impact on this as well as does what tools you currently have or are willing to buy.

Just to name a few of your options:

• Nitrous
• Cam
• Heads
• Rocker Arms
• Porting heads
• Intake manifold
• Porting intake manifold
• General tuning
• Rebuild your 305 (Recommend new heads and cam with this)
• Stroke your 305 to a 335CID (Recommend new heads and cam with this)
• Swap to a larger SBC (Get a 350)
• LSx swap
• Super charger
• Turbo charger

Some of these things range from fairly inexpensive to extremely expensive. You can also combine your options here. You could do an LSx swap and then add a super or turbo charger to it. You can also do an LSx swap with cam, heads, and a super charger or turbo charger then top it off with nitrous. Again your budget and mechanical ability comes into play here. If some of your budget involves paying for labor then what you can do for a given amount of money is diminished. If you have a lot of ability or are willing to learn, and this car isn't a daily driver you can go further on the same amount of money.

Whatever you do, I would advise against spending a ton of money on the 305. Anything beyond a cam is just too much money in my opinion. You'd be better off getting a 350 and dropping that in. It will support much more power for the same amount of money spent.