Hello,
I'll skip all the bad news that lead me to this point. Bottom line is, I have an 87 IROC-Z Convertible...previously stolen before I'd bought it, so it only has a 350 sb (pre 87) with a 4 bbl. The motor was completely rebuilt shortly after I bought it. Then, 2 rocker studs pressed out and I had to pull the heads, pull all the studs, tap 'em and install threaded studs. While at that, I chose to upgrade to 1.6 roller rockers.
Here's where my question is. I've been told that the stock heads (pistons are flat top, btw) can handle a comp cam with a 480/480 lift. Before I actually install it, I wanted to ask some of you out there...is it possible? I do understand I'll have to install at least a 2400 stall converter (and I'm going to install a manual reverse valve body while I'm at it) on the 700-R4. This car has been alot of sweat and tears due to the condition after being stolen and gutted, though mostly electrical issues.
Anyways, any help with this would be greatly appreciated. Thanks in advance!
Ace
I'll skip all the bad news that lead me to this point. Bottom line is, I have an 87 IROC-Z Convertible...previously stolen before I'd bought it, so it only has a 350 sb (pre 87) with a 4 bbl. The motor was completely rebuilt shortly after I bought it. Then, 2 rocker studs pressed out and I had to pull the heads, pull all the studs, tap 'em and install threaded studs. While at that, I chose to upgrade to 1.6 roller rockers.
Here's where my question is. I've been told that the stock heads (pistons are flat top, btw) can handle a comp cam with a 480/480 lift. Before I actually install it, I wanted to ask some of you out there...is it possible? I do understand I'll have to install at least a 2400 stall converter (and I'm going to install a manual reverse valve body while I'm at it) on the 700-R4. This car has been alot of sweat and tears due to the condition after being stolen and gutted, though mostly electrical issues.
Anyways, any help with this would be greatly appreciated. Thanks in advance!
Ace
five7kid
Moderator
close
Apr 26, 2026
Whether the heads can handle the cam really depends upon the heads. "Pre 87" 350 is a little too vague - need more info (like casting #'s).
Regardless, you can be about 100% sure you'll need new valve springs if the stock factory springs are still on there.
While the heads were off, you should have had the guides cut for positive-type valve seals. Helps both with oil control and valve lift capability.
Regardless, you can be about 100% sure you'll need new valve springs if the stock factory springs are still on there.
While the heads were off, you should have had the guides cut for positive-type valve seals. Helps both with oil control and valve lift capability.
Thanks for posting. What I can say is that the engine is roughly 75-79, but I can get the casting #'s and post them. The motor was completely rebuilt not even 5,000 miles ago, including the heads, so they're not the stock valve springs.