8/4 vette problems
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3rd Gear
Joined: Jun 2017
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8/4 vette problems
i have a 84 vette with a 383 stroker (578hp). two problems with it. 1) running way too hot at 210-225. what can be done without replacing radiator? 2) tremic 5 spd so the ladder was designed to be mounted on the top and bottom of transmission but tremec only has holes for the bottom two bolts. i autocross this car and tore off the ladder at the transmission recently. is there any mounts out there that are better. 3)i am running 275's now and want to run 305's square on the car but do not know what will clear and what won't. running 17'' right now. any ideas? thanks lee
Melting Slicks
Joined: Jul 2010
Posts: 2,999
Likes: 242
From: Surprise, Az
"1) running way too hot at 210-225. what can be done without replacing radiator?"
Short answer, not much. I would try a 160 to 180 degree thermostat but running a lot of horsepower like that is going to generate heat. A cooler thermostat will take it longer to build up the heat in the coolant. I would give DeWitts a hard look, their radiators are very well built. This also depends where you are located. It's nice to see where people are from in their avatars. For instance if you are in Arizona, I would certainly save my money if I had to and upgrade the radiator. If you were in the Pacific Northwest, not so much.
Sorry I don't have any advice on question 2, other than you might have to find a custom fabricator and have a bracket made.
Short answer, not much. I would try a 160 to 180 degree thermostat but running a lot of horsepower like that is going to generate heat. A cooler thermostat will take it longer to build up the heat in the coolant. I would give DeWitts a hard look, their radiators are very well built. This also depends where you are located. It's nice to see where people are from in their avatars. For instance if you are in Arizona, I would certainly save my money if I had to and upgrade the radiator. If you were in the Pacific Northwest, not so much.
Sorry I don't have any advice on question 2, other than you might have to find a custom fabricator and have a bracket made.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
i have a 84 vette with a 383 stroker (578hp). two problems with it. 1) running way too hot at 210-225. what can be done without replacing radiator? 2) tremic 5 spd so the ladder was designed to be mounted on the top and bottom of transmission but tremec only has holes for the bottom two bolts. i autocross this car and tore off the ladder at the transmission recently. is there any mounts out there that are better. 3)i am running 275's now and want to run 305's square on the car but do not know what will clear and what won't. running 17'' right now. any ideas? thanks lee
The temps you're running are typical of the C4. If you want cooler the you have three options...
- Cooler thermostat. Does nothing at idle but helps at speed...at least until you're pressing the engine. Might buy you one more good lap if you time trial or a couple runs for auto-x
- add hood vents
- bigger radiator...you need to consider it
For the transmission, you need to search, but I believe there used to be a modified tail shaft housing that allows you to correctly bolt the C-beam to the tranny. The stock setup uses 2 long bolts plus washers and nuts, not 4 separate bolts. Sorry, but running it the way you did was stupid.
305s will rub at full lock. Of course wheel offset also comes into play and can result in the tires contacting the fender lip when the suspension compresses. The C4 forum can likely tell you the offsets you need.
