I have a 1990 6-speed corvette with a TPI. Figured I could ask here too. You guys seem to be more help!

What the car has now:

350 bored .040 over
4-bolt mains
ported plenum
ported and saimesed base
180 degree t-stat
1.6 roller rockers
4.11 gears
Hooker headers
no precats
flowmaster 40 series exhaust

I'm looking to do a heads/cam/intake package next winter. The motor is 4-bolt mains, bored .060 over, and has hypertenuic pistons. Here's a link:

http://store.summitracing.com/partde...H423NP60&autov iew=sku

I plan on doing a modded HSR or a converted LT1 intake. Either way, I'm ditching the TPI.

I have a few questions. I'm looking to go with a set of Trick Flow heads. Would 175cc of 195cc intake ports be better for the 350? Looking for around 6k-6200RPM peak. I want to balance upper RPM capability with lower RPM torque. What are the benefits and dowsides of each runner size?

Cams: Looking for something around 224 duration at .050 with 112LSA and .555 or so lift with the 1.6RR. Would a cam like that give a nice lumpy idle? Also, has anyone run heads with 2.02 valves and that lift? Is there any piston/valve clearance issues? Is that a good cam for the 3-6k power range?

Also, on the motor, would it handle those RPMS? Any issues with clearances? Any issues with the hypertenuic pistons?

I don't plan on doing a 383 build since the motor is new.

Thanks for the time.

 

Use the Trickflow 195's, the more air the better.

Your post is kinda confusing though. You still want low end torque but you want a cam with a 3-6k rpm power range. Comp XE 224/230 will make power where you want it and you will like the idle, but if you're expecting low end like a TPI, you will be disappointed.

 

Well, I mean I don't want an upper-RPM screamer. A 6-6200RPM peak is fine for me....

I know I'd lose some down low, but so long as the 3-4k area still remains torquey, I'll be happy.

 

this is really exagerating but, the smaller runners will give you more low-mid power and drop topend, while the bigger runner will give you mid-upper and drop a bit of low..

the bigger LSA angle will give you more lowend (smaller=more topend) so i would go with the 195's.. but with the 175's, you will have KILLER lowend..

is the block zero-decked?? even if so, you shouldn't have problems with piston to valve clearance.. i ran a solid flat cam with 260 duration and .592(1.6 rocker) minus .022 lash with .040" piston to head quench.. no problems.. and its with 2.055 valves

 

Be carefull...I installed TFS 175 heads last year (small valve springs as I am running stock cam and 1.6 rr's) and I just replaced all 16 valve springs. I had 8 broken damper springs out of 16. This motor has about 1500 miles and doesn't see 6000RPM ( doesn't make any power up there so why?) so I wasn't impressed to find part of one of the springs lodged in the oil return hole. Good price....nice castings.....junk valvetrain.

 

LT1 intake or HSR will make a flat torque curve and plenty of torque to boot. I'd use that and the comp 503 cam.....224/230 with a good set of 195's and it will make good power to 6000K. AFR 180s tho wouldnt be bad...i'd stay away from the 175 trickflows for a 350..it was better designed for a smaller 305 motor with smaller bores. go atleast 180-195 cc heads....

 

well, the thing is that the AFR's are a lot more expensive. College kid here.

 

if your woried about money i'd look into the edlbrock rpm performers. the smaller runner will help with low end torque and they flow well enough for some good top end. i belive superchevy mag did a shoot out useing both, and the rpm performers held better average hp and peak hp. plus there only 1100 bucks.

 

All I know is, the local guys with Trick Flow and AFR 195 heads make a lot more power than my ported Corvette heads with 173cc (measured) ports. I would most definitely pick the Trick Flow 195's. In fact, I bought a set off one of the local guys when he upgraded to Dart 200's.

 

Well, what I like about the TFS heads are they have D-port exhaust ports....and the Hooker headers I have are also D-ports.

The Edelbrock's don't, right?

 

i'd also check out Dart Pro 1 heads... they are nice for around 1200 a set complete.

also look into the new Patriot 23 degree heads... they look like the best bang for the buck.. ebay shops have them for under 800 complete for the set and they have promising flow numbers as advertised. If these heads are like the LS1 heads they make, then you can bet they do flow extremely well

 

enginekits.com

they sell some good flowing heads..

$900 for a set of 190cc heads.. fully assembled.. aluminum too.. seems good to me

 

So what is the general concsencious?

Looks like I got my pick of Dart, Edelbrock, TFS, along with other ones like Partriot.

Which ones have D-port exhaust ports? Anything that isn't I won't buy....it'd be pointless to have D-port headers with rectangular exhaust points from the heads.

 

Trick Flows are the best bang for the buck, in my opinion. They're consistantly rated the #2 best flowing heads, behind AFR's, for 2/3's of the cost of AFR's.