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I have an 02 C5 base with LS6 intake. I am about to tear my car apart. Some of this info may be irrelevant but i'll share it just in case. lol. I have a BTR stage 3 cam, all the trunion and oil upgrades, dual springs and titanium retainers. all sitting here ready to go in.
I also have a merican performance built 4.10 3 rib diff and Z06 trans, monster twin disc clutch and tq tube rebuild about to go in at the same time lol.
Anyway... i'm sitting here looking at the parts on the shelf... and i'm thinking to myself... should i do heads? I was looking at texas speed CNC'd 243's, but then i started looking at trickflows.
My goals are mid 400's. with the 4.10's and short gearing it shouldn't need more than that to be an absolute hoot at autox and on back roads (where it lives most of the time).
Just looking for suggestions on which heads you guys would run and anywhere you'd suggest purchasing them.
IMO it depends on how long your willing to go between head rebuilds (soft guides -vs- stock hard guides) and where you want the meat of the TQ curve.
If its not a race track engine, and will live on street radials... I'd steer towards an engine build that gives me a linear TQ curve and MAX out where I'd be actually using it. (probably smaller heads)
I would recommend Mamo Motorsports (MMS) 223 Sportsmen Heads, which start out as TFS 220 as cast then
Tony hand blends the ports and chambers along with his proprietary valve job/angles with light weight valve options
for higher RPMs. Really close to the fully CNCd MMS 220s, especially on the Intake side at a considerable
reduction in cost.
A MMS Ported FAST 92 & LS2 TB would be worth 25+ RWHP at peak and 12-20+ lb'
from 2500-5500 VS LS6 intake & 78 mm tb. A Yuuge gain with your cam & head upgrade.
A Fast 102/102 combo would not provide nearly the same HP/$ IMO at the goals you seek.
You're doing 4.10s PLUS a Z06 trans? Have you driven a car with either/or yet? I'm a big fan of my 4.10s, but if you're doing heads, cam, etc on top of that, that's a lot of gearing man. You'll need some seriously sticky tires if you want to be able to use any power in the first couple gears. I honestly wouldn't be surprised if you were able to roast street tires in 3rd gear with that gearing and power. I got sideways on the freeway last weekend with 345/30/19 R888s giving it some throttle in 2nd gear at around 35-40 mph to get out of a backed up lane.
If you haven't already, take a look at this calculator first to see where your shift points, cruising RPM, etc will be: C5 with 4.10 and M12
Not trying to be "that guy", just making sure you've considered all of that before throwing more power at it also
You're doing 4.10s PLUS a Z06 trans? Have you driven a car with either/or yet? I'm a big fan of my 4.10s, but if you're doing heads, cam, etc on top of that, that's a lot of gearing man. You'll need some seriously sticky tires if you want to be able to use any power in the first couple gears. I honestly wouldn't be surprised if you were able to roast street tires in 3rd gear with that gearing and power. I got sideways on the freeway last weekend with 345/30/19 R888s giving it some throttle in 2nd gear at around 35-40 mph to get out of a backed up lane.
If you haven't already, take a look at this calculator first to see where your shift points, cruising RPM, etc will be: C5 with 4.10 and M12
Not trying to be "that guy", just making sure you've considered all of that before throwing more power at it also
Sounds hilarious lol.
4 5 and 6 are the same in the z trans as the non z trans so should be fine on the highway.
70 looks like 2150 rpm. Sounds good to me!
Last edited by 2k2wranglerx; Feb 1, 2020 at 09:37 PM.
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
5th and 6th are different, 4th is the same in all manual c5/c6 and probably the c7... the base c5 5/6 are .74/.50 and the z06 is .84/.56... I think reverse may be shorter in the z as well lol... my cruise rpm on the highway is about 2100 at 80mph, it is nice being able to use 6th without downshifting
Last edited by StingrayRebel; Feb 1, 2020 at 11:19 PM.
5th and 6th are different, 4th is the same in all manual c5/c6 and probably the c7... the base c5 5/6 are .74/.50 and the z06 is .84/.56... I think reverse may be shorter in the z as well lol... my cruise rpm on the highway is about 2100 at 80mph, it is nice being able to use 6th without downshifting
Ah ok cool. I didnt realize they had a different final drive. Thanks man
I have been on the fence and going between PRC 2.5 heads vs. taking my 243's out to Bischoff. The flow numbers appear to be very similiar.....so it's a difficult decision. Bischoff did a set of heads on a family member's viper heads that performed fantastic.
Based on your needs what I gathered is you need good shocks and a nice sidewall to handle back roads they aren’t kept up the greatest! I would do small port clean up port and rebuild the current heads. You should already be pushing 400!
Last edited by Speedy007; Feb 2, 2020 at 04:39 PM.
I have been on the fence and going between PRC 2.5 heads vs. taking my 243's out to Bischoff. The flow numbers appear to be very similiar.....so it's a difficult decision. Bischoff did a set of heads on a family member's viper heads that performed fantastic.
Talk To Nick at Skaats Precision Motorsports in downtown Cincy...90% of what he does is LS and deals with Bischoff.
He helped me put my plan together on my C5Z, and I'll top it off with a simple ported 243's. Should see low to mid 400's on a "typical" HCI build.
Last edited by smitty2919; Feb 2, 2020 at 09:24 PM.
I recommend the more affordable PRC 2.5 heads milled for 11:0.1. I am biased, but going that route will save you some cash if you want to go with the FAST manifold and LS2 throttle body. You won’t hit mid-400s without the manifold and TB. You can go crazy and spend the extra 3-5k on crazy heads and valve train if you really want. But you have to ask if that’s worth maybe 25-30 more hp. Here is my build. Dyno results are near the bottom (453rwhp/413rwtq).
Haha it was funny after the fact, but it surprised me a little at the time.
I'm an 80 mph freeway cruiser, so when I saw 2450 rpm at 80, I was like oof. I forget that a lot of people don't do 80 on the freeway lol.
even 2400 is fine. that doesn't bother me at all...
The miata 4300 rpm at 80 lol.
as long as you're out of the gas even at 2400 rpm gas mileage should be fine. and i've found with previous cars i get less drone. I'm a big fan of gear.