IROCZ28KevinZ

iTrader: (2)

Hi everyone, I am currently building a 1985 305 TPI for my 88 GTA. The TPI will be going away in favor for a carb. Here are the specs on the engine:

-Flat tappet hydraulic cam
-305 bored .010-over w/aluminum hypereutectic pistons
-new stock replacement crank and main and rod bearings
-Melling high-volume oil pump
-stock 0416 casting heads with new valve seals and valves (stock size valves)
-Hedman Headers w/ y-pipe, 3-inch exhaust with stock muffler (that will change after this engine is dropped in)

Also, car is a 5 speed, world class T5.

Now here are the performance goodies I have selected so far. I have not bought any of these, so if anyone has any input/advice, please let me know, I would appreciate it!

-Summit K1106 cam (intake/ex duration @.050 lift 234, advertised intake/exhaust duration 292, intake/ex lift .488 with factory rockers, LSA 114)

-Comp Cams CCA-981-12 valve springs (370 lbs/in spring rate)

-Holley 600 CFM carb, mechanical choke/vaccum secondary (got it from my neighbor for nothing )

-My friend reccomends an Edelbrock Performaer intake (not the Performer RPM)

-Non-CC HEI distributor

Does that sound like a decent combo? Again, if someone has some input please give it to me, I am all ears

Quinny

That cam is too big for that combo. You will need significant head work (ported, larger valves etc) or aftermarket heads, and increased compression. You will need shorter diff gears too. The Performer RPM intake would be much more suited, and I am not sure that the 600 carb would be enough. The 114 lobe separation will make it a little nicer to drive especially at low speed, but in a 305 it would still be a bit cranky.

I would probably look at a cam in the low 220s duration - something like a 222/222 .480" 112LSA.

IROCZ28KevinZ

iTrader: (2)

OK..did some more research and found a couple threads on here talking about the Summit K1102 and K1103 cams. Here are the specs for each:

K1102
Intake Duration at 050 inch Lift 204
Exhaust Duration at 050 inch Lift 214
Duration at 050 inch Lift 204 int./214 exh.
Advertised Intake Duration 262
Advertised Exhaust Duration 272
Advertised Duration 262 int./272 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.420 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.442 in.
Valve Lift with Factory Rocker Arm Ratio 0.420 int./0.442 exh. lift
Lobe Separation (degrees) 112

K1103
Intake Duration at 050 inch Lift 214
Exhaust Duration at 050 inch Lift 224
Duration at 050 inch Lift 214 int./224 exh.
Advertised Intake Duration 272
Advertised Exhaust Duration 282
Advertised Duration 272 int./282 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.442 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.465 in.
Valve Lift with Factory Rocker Arm Ratio 0.442 int./0.465 exh. lift
Lobe Separation (degrees) 112

How about one of those? BTW, I forgot to mention in my original post the car has 3.27 gears. I do have a rear with 3.73's in them that may one day find its way into the car, but I dunno about that right now.