My question is will a 454 tbi engine fit in my 89 rs? I found one for fairly cheap and i am wondering what kind of stock horsepower they have and what modifications would i have to make to get it to fit? Thanks alot.

 

235 FWHP/385 FWTQ

The engine makes peak torque at 1,600 rpm!

I am putting this in for reference. I have one of the TBI 454s, it is pretty dogish in stock form. A stock 350 TBI unloaded in the same truck will run away and hide from it. Loaded is a different story though as the TQ is much greater at a much lower engine speed. I pulled one from a one-ton van and have it stashed in my garage. As installed in the 1-ton G-series Van with a 4L80E and 3.73 gears, it would fry the tires, but was slower than my TBI 350 once rolling. My 1997 Express' stock 350 Vortec would rape it at all speeds!

 

So would it fit or would it be a waste of my time...? I need to know if the stock 7.5" 10 bolt rearend would be able to handle the torque, and if i will have problems with the headers hitting the wheel wells and if i would have enough hood clearance.

 

My 91 454SS has a Gen V TBI engine. It's rated at 250 hp but on the dragstrip, I've done a calculated hp of 307. (It's had a few things done to it) It's enough to move a 4600 pound truck to 15.0's. Estimated torque is about 400 pounds feet.

The engine in that picture is a Mark IV BBC. They were produced up to 1990 then in 1991, GM started building the Gen V engine. 1991 was also the year the 4L80E tranny was introduced To my knowledge, GM never offered the 4L80E behind the Mark IV BBC. It's probably only a TH400.

As for the swap, there's a sticky at the top of this forum on doing a BBC swap.

 

Its from a 1991 G30 and it is definately a Mark IV and definately a 4L80E, not a turbo 400.

 

As far as the swap goes, its the same as a regular BBC swap (ie. Mk IV) except that you would need a flywheel/flexplate for an external balance and also for a 1pc rear main seal. Any other differences between the Mk IV and Mk V are internal things, like roller lifter provisions, etc.

I *think* the 4L80 trans has the same dimentions (at least as far as mounts and things go) as the 4L60 A.K.A 700R4. It *should* bolt up in place of the 700R4, but I'm not 100% certain of that.

 

The 4L80E has its own mount location and a different length of driveshaft. It is a MASSIVE transmission compared to a 700R4. It is bigger than a TH400 which it is loosly based off of!

 

I stand corrected.

 

Just wanted to let him know so that he doesn't go into the project thinking it will "Bolt Right In".

 

Pssst.... thats me being slapped in my post.... lol

Well its good you said something. I don't wanna be the one to f*ck the guy over on his swap.