I have recently got a 454 that my uncle gave to me cuz i have been begging for it sense he took it out of one of his cars .. he says its rated at about 455 HP .. but a guy who was going to drop it into my car said if he puts it in there and i stomp it that i will twist my chassis .. is that true .. i mean i know the guy knows what hes talking about but will that really happen if i out it in my car .. i have a 1991 firebird that currently has the 305 TBI .. thanks for any info

 

My car came with a carbed 305 and it already had the tell tale cracks just above the windows, so if a baby 305 can somewhat tweak a uni-body, you can just imagine what a 454 with that kind of hp is gonna do. Definately invest in sub-frame connectors, and if time and money allows in the future at least a 6 point cage.

 

Consider this. At one point GM didn't offer the T-tops option if you checked the 350 TPI option box because they felt that the chassis could not take it. If they were weary of a 240hp, 335lb/ft engine twisting the chassis, then what do you think that 455hp 454cid bigblock is going to do to your poor chassis?

First time I put the front end of my GTA up on jacks to get to the exhaust down pipes I thought I had ruined it permanently when the doors no longer lined up with the body! All was well when I dropped the car back down, but it was still an enlightening experience.

 

It's been done before and is going to be done again, just get some quality subframe connectors and all is well.

With the cost of everything your going to put into the swap good SFC's are one of the cheap items.

 

Its not that it can't be done. Its just that a stock body can't take that kind of torque. I'd personally love to see it done. If I had the money, and the patience I'd do it myself. But it'd take me forever to do it as while I know the theory of everything I dont' know the reality. Theory is vastly different from reality.

 

There are several people here that have already done it and I myself am about to start it. I have 90% of what I need and I'm working on finishing up the BB. I'll have it running by spring.

True the stock body can't take it but isn't that what SFC's are for?

 

My T-top car originally came with the L98 5.7L TPI. With the BBC, I've had no problems with the T-tops. Of course I also have SFC and a 6 point roll bar.

 

Stephen, my car came with T-tops too, and the 350, so GM did start making them, its just that for a while GM didn't produce them because they were afraid the engine would be too much for the chassis. Guess they were proven wrong, but still the stock body does have ALOT of flex in it.

 

Well, Stephen's is an 87, and that was the first year for the 350 in a thirdgen so I think someone was telling you stories or something.

Ben

 

I remember reading it off of a site, so I'll have to go searching for it. But I do remember reading it somewhere. No one just knows everything, you have to read/learn it from somewhere. And not all sources are correct, so maybe the source I read was wrong. But hey, I was 7 years old when the TPI engines where introduced to the Fbody. At that time the only Fbody I wanted was KITT, and I just wanted KITT, I didn't know it was a Fbody.

AHA! I knew I read it somewhere. Please forgive me, this was for the 1990 model year. The following is a direct quote with a link to the article. If you go directly to the article you'll need to scroll down to the 1990 model year. I've made the text bold. You were right, T-tops were offered right from the start with the TPI 350 engine, but in 1990 the L98 engines did not come with T-tops because pontiac feared that the chassis would twist.

Quote:

Drivers side air bag now standard. Firebird interior again meets a redesign, this time the changes are much less drastic. Pontiac changes the lower dash and underdash panels. Accessory switches get new panel above heater and radio controls. Shoulder belts are added in the back. Console gets new shift indicator and different leather boot. Steering wheel mounted radio controls disappear from the GTA with the addition of the airbag. L98 cars no longer offered with ttops due to excessive torque and limitations of the unibody construction. Like the 1990 Camaro, Firebird also only received a half year production as Pontiac raced to release the 1991. LB9 and L98 platforms updated with new speed density fuel injection. The elimination of the MAF sensor allowed for cheaper production costs and improved performance.

This site seems pretty accurate, so I'll beleive it till I get proof otherwise.

 

So, then would that mean that 90 was the only year to not have t-tops on a 350. I do not know for sure, but thought that 91 and 92 had them available. Oh well, I would rather have a hard top anyway, so that is what I have.

Ben

 

Just get a basic set of subframe connectors and let it rip. Upgrade other things as you see fit. Nothing like just driving a car to figure out what needs to be changed.

 

I run an 8 point bar in my car (no sfc's). 4+ years and no problems.

Miles
www.koolmeister.com