Grand National clone build

[1985cutlasssupreme]

Thanks.
It is finished - took it to a car show Friday night.

i really like those back tires. nice car do you have any videos of it?

 

[dogsht]

My buddy has 255/50/16s on rear his GNX. 245s up front.

 

[LS1GN]

They're 245 50 16 Nittos - got 'em off Craigslist and mounted 'em on my garage floor.


As far as quarter times, One thing that really helped was working on the transmission governor - getting it to shift later allows the engine to pull harder, longer. I bet I picked up 50 hp by shifting at 6000 rather than the stock 4200 or so.

The trans governor is REALLY EASY to R and R - seriously

 

[79loserbluebu]

6000, that's it? I think mine is set at 6500 at WOT and still have some RPM to play with. Don't be scared these engines take a beating and a half. I'd be willing to bet you'll gain even more everytime you run the car down the track.

 

[uneek1976]

Great thread do you have the part number for the trans dapt mounts and what headers did you go with? Again great build.

 

[dogsht]

Yea most of the generic gbody 200-4Rs shift at 4,200 the 442s at 4,800 the GNs at 5,200 and the MCSS at 5,600. I always wondered why they were 400 rpms increments or whether it just happen that way. The original trans I had built for behind the 509 was from a Ttype so it shifted at 5,200 which was perfect for the 509 so I never had to work with shift points.

 

[LS1GN]

Motor mounts: I don't have the number right off hand but they are Trans Dapt for a Chevy S10 to LS1 conversion. I did have to drill some new holes in the K member.

The headers are for a 98-02 Camaro/Firebird - had to "shape" the passenger side with a hammer and a torch

 

[LS1GN]

6000, that's it? I think mine is set at 6500 at WOT and still have some RPM to play with. Don't be scared these engines take a beating and a half. I'd be willing to bet you'll gain even more everytime you run the car down the track.

still have the original valve springs

 

[LS1GN]

Bad news guys, junkyard transmission # 2 is now starting to slip

You spend $75 bucks on something and it just doesn't last - need to start saving $$$ for a new race 700R

 

[dogsht]

http://WWW.extremeautomatics.com. Lonnie did two for me with great results. Both held up behind more torque than the LS1 which is what breaks transmissions more so than HP. $1,495 guaranteed to 500HP or 10.90s for one year no core charge unless you want the BRF core. He can set shift point at 6,000 rpm no charge.

BTW why step down to a 700 & have to cut your driveshaft etc to make it fit? Built they generally cost just as much.