Unless you go 243s or l92s id stay with the 317s. Same flow as 243 just lower compression and that means 87 octane...cheap and itll easily meet your goals

 

I ended up picking up a set of 241s with aftermarket springs at the right price. If nothing else I will swap the springs between the 241s and the 317s and run the 317s. I am still weighing my options right now. Thanks for all of the advice from everybody. It really helps out to have some opinions and real world experience to look at.

 

Nice find, i keep forgetting how easy it would be to swap heads in an engine bay with that much room. I hope to never have to switch mine once engines in ha

 

Yeah there's a ton of room. The clearance issues on these cars are header to frame and power steering pulley to steering box. Other than that, they are pretty roomy.

 

Since you have the 241's now, go ahead and do some porting on them and mill some off to get your compression up....you will be happy with them

 

That's probably what I will do. I have access to a head surfacer, so I plan to mill them myself. I may throw a small port job on them and see how they turn out. If it doesn't do what I want I will still have the 317s to mill down or fill the chambers in on. I couldn't really pass up the deal on the heads, the springs alone were almost as much as I paid for the whole setup.

 

Good info. I have stock 241s on my GTO, but I've been seriously considering the upgrade or getting my ported.

 

on my 370 i have 241s, and made 440whp 413 tq, with bolt ons and ls6 mani, stock 241s and tb.

 

I like the sound of that.

 

thats with a pretty big cam, were you camming yours?

 

I am, but I am going small. I am shooting for somewhere around 350rwhp, not much more if any.

 

yeah forgot to mention thats with the Trex cam, shes a big bitch

 

Not when you put it up against my 255/271

 

yeah thats deff a bit bigger then Trex, dang lol. street driven?

 

Was my dd before this winter when i took it off the road to do some more things to it...408 though, not a stock cube

 

There are many bolt on cars making that power.

With a large cam, cam only cars have made 450rwhp with a 6 speed and a FAST intake.