MrElectric03

iTrader: (71)

Alright guys...I have a 68 Firebird 400 4 speed that I am about to start working on. Non-original motor, is now a TH400 trans but have a Muncie on the way. I know this is an LSX site and I love the LS1 in my 01 WS6 but I want this car to be somewhat original so no T56s or LS1 swaps.

I am wondering what kind of upgrades you have done to your motors weather they be a 400, 455 or whatever pontiac you have in it but am really interested in the 400. I plan on rebuilding the motor, maybe a bit more compression, aluminum heads, performance parts, headers ect. What kind of performance or horsepower have you gotten from them and how is the drivability?

Thanks for the info guys I really appreciate it, im looking forward to FINALLY having an old school muscle car.

IRONFIST

Bro, I love my 400. It's balanced, built, blue-printed, and rev's up real fast. BUT honestly, I wish I had gone with a 455. I have some buddies with 455's and the low-end torque they have is amazing.

IRONFIST

Hey I didn't have much time last time I posted to get into things. I actually went with cast iron 6x-4 heads, but I was young and broke. I'd go with Alum' heads, probably edelbrocks. Other then that, my 400 has a performer RPM intake, XE 274 cam, and is completely balanced. It needs good gears and a stall to be driveable. And puts out about the same amount of power as an LS1. If I was to do the same build up, and simply used a stroker set-up and built a 455 out of my engine, it would probably produce about 100 more horses. The increase in compression, and displacement, would help a lot.
That's on the list for future upgrades...

MrElectric03

iTrader: (71)

Thanks for the info!

I am looking into the stroker kits sold that turn the 400 into a 461. Im not looking for a race car or anything, just a stout weekend car to take to shows and on cruises. I want it to be reliable so im not going too wild with it. On the outside it will be all stock but drop spindles, wheels and a rear spoiler. Under the hood i want it to be stock drivetrain and would like ot keep the 400 block, 4 speed muncie, and 12 bolt rear.

Thanks again for your help!

BAD2000TA

iTrader: (6)

Go to the Performance Years forum. Lots of old school Pontiac knowledge.

http://forums.performanceyears.com/forums/

Oh, I love my 455's torque, too!!!

IRONFIST

Well if the engines good, the 400 is plenty powerful. But for the future, at least, do as I'm doing and keep the 455 in mind.

MrElectric03

iTrader: (71)

Thanks for posting that...Ill have to look around on that forumn.

joelvette

iTrader: (11)

also try transamcountry.com another very busy older pontiac site