Intake, worth changing?

I/ve got a 84 Merc 228, I/O, 305 chevy. Should be close to 300HP now.
Would it be worth changing the stock intake to a performer. Myabe even the air-gap design? I've heard both, do it, and not gonna do any better than the factory stuff.

IMO the stock intakes are not very good. Plus an aluminum intake will also weigh less and doesn't rust. I'm sure if your's is the original, it is most likely very corroded inside. A performer would be a good bet. Low cost and would help your motor breath.
Darrell.

The Performer and Air Gap Performer (not to be confused with RPM airgap) are perfectly sized for the stock thru warmed over 305's. If running 6k plus then the RPM series will become better.
The factory 4bbl cast iron intakes are okay until aprox 3800rpm on a 5.7 and approx 4200 on 5.0. Anything over this and the aftmkt intakes will really shine. You'll lose no bottom end with Performer or Performer Air Gap.
If you use the performer (not air gap) and don't have choke or are willing to defeat the choke make sure to use the Fel-pro 1204 intake gaskets that have blocked heat cross-over intake gaskets. This is assuming your not using Vortec heads of course.
If you are using a flat tappet cam then I'd also suggest installing a lifter valley oil shield from Moroso, Cantaon, or etc. Hot oil really heats up aluminum intakes.

Before I would recommend an intake, what mods have been done on your 305 to make it close to 300hp? For a relatively stock 305 a performer is a good choice. Less weight and a little more power.

I think a Performer Air Gap would be a very good change, but don't expect a huge change like another 50 HP, 10 or 15 maybe, and then it is unlikely to be very noticable. The weight loss is a valid issue, and I think cfm's figures on the choke RPM points of the intakes are likely very close.
Yes, what mods have gotten you near 300 HP? The intake could be more bennefit than innitially of thought if you have made it a real restriction in the whole setup.

Remember, if you are running under a hatch, the air gap is doing you very little to cool the intake charge. It was designed to be in a car with forcefull air flowing through it. If your engine is exposed, you will get a benefit from an air gap style. Other than the air gap, you have many choices.

ASSUMING the motor had 228 to begin with. I have:
Valve job and cleaned up the bowls and matched the gaskets. This was done with the help of who "Motor people" down here consider a genuos with heads. Thats all he has done for 20 years. He also the shaved heads and intake by .060. Which should have raised the compression to 9.5.
He picked out a cam that has given this thing an unbelievable amount of torque. As he said it would. Roller rockers, 1.6 and T/T exhaust.
Thats was 2 summers ago. If memory serves me correctley I was told, approx. of course.
Valve job 30 HP
Cam 30HP
Compression 10 HP
Roller rockers 10
T/T exhaust,what 10hp?
I wouldn't swear on these #'s. But I'm hoping I'm atleast at 300. Maybe a little more.

Well?::confused:

A performer will do a great job on your motor. You should pick up torque across the board and pull some better HP numbers on top.
Darrell.

Performer, unless your spinning the motor over 5500rpms then you might want to go for a Performer RPM.