It looks like the 350 TPI motor I have always wanted will be here soon. My question is are you better off ordering aftermarket heads or sticking with stock heads but having them ported and polished? Besides some weight differences are their any differences or big hp gains with new ones? Any input/reply is greatly appreciated.

------------------
91 rs
3.42 gears,3" flowmasters,180 deg stat,custom prom,and a new 700r4 with shift kit and all the go fast goodies.

 

Any aftermarket head is better than factory. Even porting and polishing factory heads has it's limits. Usually it brings them up to spec with the aftermarket heads in flow but not in design or extras like larger valves, screw-in studs, extra casting in weak areas etc.

------------------
Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block (times are for the current engine)

Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586

Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

If you have the money go with the market defeniately.

Stock 350 heads are of old design. The chamber design is old and there are many imperfections with them.

I am on the tight budget so I will be sticking with my stock heads.


But them again if you are an expert porter you can make the L98 heads flow close to many aftermarket heads.

 

Cool thanks for your help. The only reason I really bring this up is because I have heard it go both ways. Some say upgrade to new aluminum heads and some say port your old ones and you won't notice a difference between the ported ones and new ones. I figured buying new ones would be the best thing to do, but not enough money just yet. I still have to get the motor here, get it rebuilt, and get it installed before I jump into other areas. Damn it, Lots more money to spend in the next few months.

 

who said u need to get aluminum heads, cast iron after market heads(ie dart Sportsmen II) will out flow any ported stock heads and there resonable preiced

------------------
when the green flag drops the bull$hit stops

Gold 85 Camaro with no motor, pulled the 2.8 to make way for a 350 wich was pulled this summer because a 406 will replace it. The 406 sports a stock bottom end with ARP bolt holding it togeter, flat top hyper pistons. Comp 282 solid cam(.528 lift with 1.6 rockers) Savin up for my Sportsmen 2 heads right now. still Have the perf RPM and 650 DP i used on the 350. Headers and 3inch exhust. Shooten for mid to low 12s next summer

 

What you may want to also consider is getting some older High Performance stock heads.

For example a set of "Camel Hump" SBC heads will get you 10.00+ compression, with 2.02/1.60 valves. The best part is that you can get them for a couple hundred bucks in swap meets. Spend a couple bucks more on porting, and you have a great flowing head almost on par with a ported aftermarket head, for about half the dough.

------------------
1991 Firebird Formula 350
12.92@108 -At 5800 Feet!

 

test

------------------
1986 Camaro Sports Coupe
Flame Red Metallic with Black accents and Red interior
T-tops, variable wiper, power hatch, rear defrost, third brake light
LG4 305 V8, Hooker Shorty headers, 3" pipe into Walker Quiet Flow dual exhaust
Edelbrock Performer intake, "Damonized" Q-Jet 4bbl, K&N filter
Crane vacuum advance kit, Proform 50,000 volt HEI coil and MSD 8.5 mm Super Conductor wires
TH700R4 transmission and Derale cooler
Air conditioning, power windows, power door locks, power brakes, power steering, tilt wheel
Kenwood cassette, Pioneer 6x4 component front speakers
Rockford Fosgate 6x9 Punch rear speakers
Z-28 front and rear sway bars
Aluminum slots and Goodyear 225x60R15 Eagle HP tires
243 horsepower and 326 foot pounds of torque at the flywheel
_ _ _ _ _ __ _ _ _ _ _
Yea verily, and he smote the smog heathens from his small block Chevy, even from the air pump to the converter ...
Todd 1:1

 

If you're thinking you may want to upgrade your TPI (which you should if you're doing anything to your heads or buying aftermarket) go ahead and get a set of Vortec heads and a TPI baseplate to fit... That'll be the best performing "cheap" setup you can get.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray