[74GP455]

Hi all, new here and looking for some help/advise. Will give my details quick:
1974 GP, 4350 lbs with me in it.
Complete engine rebuild approx 3 years ago, runs strong:
455, .30 over, 1974 4X heads from a 400 (98cc) no port work, intake 2.11, exhaust 1.66.
Edelbrock performer, Holley 750 vac secondaries.
Crower 60919 cam, rhoads lifters, Harland sharp 1.5 roller rockers.
Ram air 2 1/2 manifold, 2 1/2 exhaust with X pipe.
TH400, hurts hot shift 2 kit, trans cooler.
3.42 posi, 275/60/15 Nitto drag radials (28 in tall)
Currently: Neal chance 11 in converter 2000-2800 stall (from the 90s, I put it in there cause I had it on hand with intent to swap out at some point)

No dyno numbers to show you all, but I think I’m making 375-400 hp based on ETs, weight and speed. Not sure on torque.

Car runs high 13s, with a best of 13.7, 96-97 MPH.
60 foot times of 1.9-2.0

I spoke with Protorque about my set up, wanting to get the car out of hole better. Car is driven to shows and cruise nights, not concerned with gas mileage. When I go to the track it’s trailer so I’m not driving it for long periods over the open road. I told him I want to get the most out of what I have, so he recommended the 9.5 pro drive model, 3500-3800 stall. They make them in 2800-3200, 3200-3500 too. He told me that if it’s too loose after a few runs, they will adjust it back at no charge (just my labor and shipping, ugh) but I’d love to avoid that. He said the modern converters they build are not like ones of old. It will be very driveable when cruising down the road at normal speeds. But when you mash the throttle, that’s when you’ll feel it.
For me the converter issue is kind of black magic, but guys I’ve spoke with said go with whatever they recommended.
I’m hoping someone maybe has a similar wght car and set up that can give me some feedback on what stall MAY work better for me.

[nikrnic]

Yes, Black magic for me too since I'm no engine builder. Just going by gut I wouldn't think to go more than 32-3500, that sounds like it would make a good launch to me and I'd be afraid of any street drivability to go higher. Don't flame me please, just saying and not apples to apples but I had a high winding small block Nova that ran 10.5s and liked to leave at 5k topped out at 8200 rpms but knowing Pontiacs don't like to rev over 5500 (thinking) and your 60ft is not too shabby now a 3200-3500 sounds like a good number. Just my .02, I have a 4spd Gto now so i certainly stand to be corrected, im really just guessing but 3500-3800 just sounds a little much for street and strip. Happy choosing, its sounds like you have a good combo you've put together.

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[Half-Inch Stud]

11" converter might be fine. Sure your got 1st on pull-away!p?

Electric pusher pump and Q-JET and i think your in the high 12s.
+0.1 sec per 100 Lb, so 12.8 ET would be SMOKING.
See signature for compares

[TCSGTO]

What part of the country are you in? Do you run at higher elevations?

It seems like you’re down on power a little. Should be able to turn over 100mph with that combo. Before you spend money you might not have to, make sure you have full throttle. Also get softer springs for the vacuum pod on the Holley 750 and see if opening the secondaries sooner helps. And check fuel delivery like mentioned above.

[74GP455]

Originally Posted by TCSGTO

What part of the country are you in? Do you run at higher elevations?

It seems like you’re down on power a little. Should be able to turn over 100mph with that combo. Before you spend money you might not have to, make sure you have full throttle. Also get softer springs for the vacuum pod on the Holley 750 and see if opening the secondaries sooner helps. And check fuel delivery like mentioned above.

I’m in NY, on long island. Tracks are in NJ.

[74GP455]

Originally Posted by Half-Inch Stud

11" converter might be fine. Sure your got 1st on pull-away!p?

Electric pusher pump and Q-JET and i think your in the high 12s.
+0.1 sec per 100 Lb, so 12.8 ET would be SMOKING.
See signature for compares

Def in first, I manual shift it. Been thinking about going to q-jet for a while. And an RPM intake too.

[yahooskidoo]

Call Cliff.

[433lemans]

Yup. Cliff Ruggles and/or Jim Wiese at Tri-Shield Performance.

[72LuxuryLeMansLa.]

Originally Posted by 74GP455

Def in first, I manual shift it. Been thinking about going to q-jet for a while. And an RPM intake too.

I'm no expert, but I start here...

[74GP455]

Originally Posted by yahooskidoo

Call Cliff.

I actually tried to send him some kind of link through this forum to have him take a look at my post but couldn’t seem to figure it out. I’ll try to google a number for him. Thank you

[77 TRASHCAN]

Originally Posted by 74GP455

I actually tried to send him some kind of link through this forum to have him take a look at my post but couldn’t seem to figure it out. I’ll try to google a number for him. Thank you

www.cliffshighperformance.com 1-740-397-2921 Cliff answers the phone!

[74GP455]

Originally Posted by 77 TRASHCAN

www.cliffshighperformance.com 1-740-397-2921 Cliff answers the phone!

Thank you!