91 GTA 350 Cam Question
91 GTA 350 Cam Question
Hey guys, New to the 3rd gen site, I've been a T/a fan for years. I built 78 trans am,
Just got myself a nice 1991 CTA with a 350/700r4
Now, from reading I think it has the corvette heads? l98?
If so, I have a lt4 hotcam kit that I would love to install. Other then needing a set of 1.6 rollers, should I have any problems?
Let me know,
also plan to install a 2200 converter and a set of headers.
place I'm stuck is the tuning?
Just got myself a nice 1991 CTA with a 350/700r4
Now, from reading I think it has the corvette heads? l98?
If so, I have a lt4 hotcam kit that I would love to install. Other then needing a set of 1.6 rollers, should I have any problems?
Let me know,
also plan to install a 2200 converter and a set of headers.
place I'm stuck is the tuning?
Joined: Sep 2005
Posts: 27,871
Likes: 2,430
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: 91 GTA 350 Cam Question
The Corvette L98 and the F-body L98 didn't get the same heads. So no, yours didn't come with the Vette heads. Doesn't mean that's not what's there now, only, didn't come that way.
The LT4 HOT cam isn't the best match for TPI. Ruins the resonant tuning (the "T" in "TPI") and moves the power RPM band up beyond where the intake supports it properly. Usually a net negative to jam that cam into an otherwise stock TPI motor.
You'll have .525" lift on both valves with that cam and 1.6 rockers. You'll need different valve springs, and maybe head machine work as well, to use that combo in your motor.
I'd suggest selling that and buying a cam more suited to TPI. The Comp 502 grind is one known to work well in a stock L98. It agrees with, and cooperates with, the properties of TPI, instead of fighting it.
Converter & headers are a good idea. Gears would be good too, yours are most likely 2.73, 3.23 makes a HUGE MASSIVE improvement.
The LT4 HOT cam isn't the best match for TPI. Ruins the resonant tuning (the "T" in "TPI") and moves the power RPM band up beyond where the intake supports it properly. Usually a net negative to jam that cam into an otherwise stock TPI motor.
You'll have .525" lift on both valves with that cam and 1.6 rockers. You'll need different valve springs, and maybe head machine work as well, to use that combo in your motor.
I'd suggest selling that and buying a cam more suited to TPI. The Comp 502 grind is one known to work well in a stock L98. It agrees with, and cooperates with, the properties of TPI, instead of fighting it.
Converter & headers are a good idea. Gears would be good too, yours are most likely 2.73, 3.23 makes a HUGE MASSIVE improvement.
Re: 91 GTA 350 Cam Question
The Corvette L98 and the F-body L98 didn't get the same heads. So no, yours didn't come with the Vette heads. Doesn't mean that's not what's there now, only, didn't come that way.
The LT4 HOT cam isn't the best match for TPI. Ruins the resonant tuning (the "T" in "TPI") and moves the power RPM band up beyond where the intake supports it properly. Usually a net negative to jam that cam into an otherwise stock TPI motor.
You'll have .525" lift on both valves with that cam and 1.6 rockers. You'll need different valve springs, and maybe head machine work as well, to use that combo in your motor.
I'd suggest selling that and buying a cam more suited to TPI. The Comp 502 grind is one known to work well in a stock L98. It agrees with, and cooperates with, the properties of TPI, instead of fighting it.
Converter & headers are a good idea. Gears would be good too, yours are most likely 2.73, 3.23 makes a HUGE MASSIVE improvement.
The LT4 HOT cam isn't the best match for TPI. Ruins the resonant tuning (the "T" in "TPI") and moves the power RPM band up beyond where the intake supports it properly. Usually a net negative to jam that cam into an otherwise stock TPI motor.
You'll have .525" lift on both valves with that cam and 1.6 rockers. You'll need different valve springs, and maybe head machine work as well, to use that combo in your motor.
I'd suggest selling that and buying a cam more suited to TPI. The Comp 502 grind is one known to work well in a stock L98. It agrees with, and cooperates with, the properties of TPI, instead of fighting it.
Converter & headers are a good idea. Gears would be good too, yours are most likely 2.73, 3.23 makes a HUGE MASSIVE improvement.
Great info. As of right now the car is as stock as they come. What lift would I get with the comp cam? what head is on this engine? vortec?
Joined: Sep 2005
Posts: 27,871
Likes: 2,430
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: 91 GTA 350 Cam Question
http://www.summitracing.com/parts/CCA-08-502-8/
Looks pretty similar on paper, but it's not as close as it looks.
Your motor would have come with 083 castings. No telling what's there now, you'll need to check and be sure.
Looks pretty similar on paper, but it's not as close as it looks.
Your motor would have come with 083 castings. No telling what's there now, you'll need to check and be sure.
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Aug 23, 2015 11:49 AM