Swap to a 454 in a 81 trans am

Hi, I was wondering how hard it would be to put a 454 in my 1981 trans am I'm wanting to switch to a BBC and 455 are to hard to find.  

What engine did the car come with from the factory? The reason I ask is because a factory 305 car will be much easier to swap than a 301 car simply because the wiring, fuel lines, battery etc are on opposite sides on the Pontiac engines. Let me know and I'll help you out. I had to reverse this swap to return my 79 Formula (originally 301 4bbl) to real Pontiac power (75 350) after I bought it with a worn out 454.
To be honest, even though real 455's are getting harder to find, 400's are still relatively easy to find and Ohio Crankshaft sells a stroker crank with 3" mains to convert a 400 to a small main 455. The upside, if you have a 301 car, people who don't know pontiacs will never know the difference until you beat them! Also most Pontiac guys will respect you more with a true Pontiac engine, most of us frown on Chevy motors unless Pontiac built it that way.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

The 81 has a 301 in it and although I don't like the idea of putting a chevy engine in a Pontiac I'm a college student and have low funds and I can get a 454 a heck of a lot cheaper than a 455 or 400 and making a 455 also I'm tearing out the computer and running a straight engine since the computers in the 81 since it was the first year wern't very good. Thank you for your response  

OK, things to consider for this swap...
-motor mounts and block brackets, you will need the small block Chevy frame mounts and big block brackets.
-accesory brackets and pulleys, you will need BBC parts for a car application, truck parts likely won't work.
-exhaust manifolds or headers to fit 2nd gen Camaro with 396-454. Most cast manifolds for BBC are crap and crack easily, good luck finding used ones that haven't been welded.
-fuel lines, Pontiac lines run down the driver's side, Chevy pump is on the passenger side. Either replace lines with ones for a chevy powered car or run a line across the front of the crossmember.
-wiring, get a harness for a SBC car or try to modify yours. The computer controls can be left unhooked. The main things you need are the starter wiring/alt wiring and two wires for the HEI. the big pink wire goes to the HEI BAT terminal and the TACH wire (usually brown) goes to the TACH terminal. There will be other wires for temp guage, choke, A/C if equipped. These don't go through the computer.
-power steering pump and hoses are different for the chevy as well, the pump is the same but the brackets on it are way different.
-trans, depending on the trans you have now, you may need a trans. Chevy bell housing pattern is different than Pontiac, some th350's had both patterns. If you build the engine for decent power, you will need a th400.
-rad hoses are different, 3 core rad will work, 4 core is better.

Hopefully some of this gives you an idea of what you are in for. It may not be cheaper in the long run. Most mid 70's and newer 454's will need some work to make decent power as most had junk heads/intakes/cams. Honestly, many mild 350's (including the "stock except for cam" Pontiac 350 in my Formula) will run rings around any stock 74-87 454. If you found a complete 400 from a 75-79 TA for around $500 (they are out there) and rebuilt it using the Ohio crank $295 and a kit from summit (around $600 plus machine work) you will have a bolt-in engine that will have some real power. Just a thought. Of course this all depends on how good a job you want to do, I know guys that will jam that 454 in a day and have it running, but how good it looks or runs will be questionable.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

Thank you very much that's a huge help I might just take a small loan and do a 455  

Just another thought, there are other options besides the 455. How fast do you want to go? Is the car primarily a cruiser or do you want to race it? 350 Pontiacs are relatively cheap ($400 for mine)because there isn't a high demand but they do make respectable power. Check my Formula or Pontiacman8's 350 Pontiac powered Buicks in "Reader's Rides" for some inspiration to that end. My Formula runs mid 14's on a nearly untouched 1975 engine with a stock converter and 3.42 gears. Other than the Crane cam and lifters, new gaskets and timing set, my 350 is original Pontiac. Pontiacman8's cars are considerably modified, but quicker. I currently use a Th400, but a 200-4r overdrive would really lower my cruise rpm. Check them out!
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

When you go to reader's rides, my Formula is right next to Pman8's regal under the heading "Most Popular".
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

Yeah I'm looking for a torque monster though. And I can make a 455 with minimal performance mods and have 550 torque numbers with low cost. I can take a 350 and get 500 torque numbers for like 4 grand if I get deals. And I can do the 455 for 2 grand at most  

Your cars gorgeous I which mine was in that good of shape. Restoring mine I'll have pics soon I also have a 1994 trans am with the 350  

I would be careful with that much torque you will have to beef up other things as well so it can handle it.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Yeah I bought subframe connectors will that be enough?  

You will probably have to beef up the suspension, the rear end and have a well beefed Th-400 transmission and a good quality aftermarket converter as well.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Oh and if you do change your mine and deside to go with a Pontiac 350 let me know and I can post a good combo for it.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

A 400/462 stroker is another option if you can't find a 455- it's also easier on the bearings and will cost about the same to build up as a 455. Both will make the same power (475-500+ ft-lb.), but you'll need a set of ported 6X's at the very least.

Geno