i have an 84 carbed 305 engine out of a 4x4 blazer in my 88 camaro and so far i have put on the edelbrock performer intake and 600cfm carb. would it really make much of a difference if i added the performer heads from edelbrock? also should i install the performer cam and lifters?..... remember its a 305 not a 350 and i have gotten rid of all the emmission parts.

 

the heads would help a fair bit. Performer cam and lifters I wouldn't recommend.

Have you swapped out the exhaust yet?
what year blazer motor is it? ie, roller or flat tappet block?
I wouldn't go too wild on brand loyalty, just spend your $ on what'll give the most bang for the buck.

 

Stock 305 heads (all 305 heads) are about 58cc in the cmbustion chamber. If you bolt on larger 64cc heads like the Eddys you will drop the compression ratio. You can end up tanking it pretty bad, too, if you use a typical (thick) rebuilder head gasket. Yes, the heads will flow better than stock, but you can lose considerable compression and end up giving back much of that power, especially in low end torque where you really feel it when you lay into it.

Trick Flow just came out with some true performance aluminum heads for the 305 with 56-58cc chambers that will keep your compression where it is if you use the right head gasket. That might be a better choice on a 305 vs. buying 64cc heads and milling them down to 58 before you ever bolt them on.

A stock 305 cam is almost always a super-wimp. Even the very mild Edlebrock Performer cam (also sold as the Summit house-brand cam #1102 for a lot less money) would be a fire-breather compared to stock. And a cam swap would be a lot less money than a set of aluminum heads.

 

if i keep the stock heads and get them ported and polished would that help?



i think its the flat tappet lifters also.

 

Of course.
How much depends on what heads you're starting with. Casting #'s are helpful to identify that.

 

were are the casting numbers?