could you hook up a 283 chevy motor in a 91 friebird formula t5 5 speed? if so what changes besides the ecm/pcm would have to be made?

 

What was the 283CID engine from? That will determine what would need to change. PCM, oil pan, exhaust manifolds, etc. might all need to change.

 

Differences between a 283 and a '91 SBC:

- 2-piece rear main seal (would require a different flywheel for the T5)
- Driver-side dipstick (would interfere with 3rd gen exhaust manifolds)
- If factory heads, no accessory bolt holes (serp system, or any 3rd gen system, for that matter, won't bolt up)
- If factory heads, center two intake manifold mount bolts at different angle than '91 manifold
- If factory heads, exhaust valves and seats not hardened for unleaded gas
- Less displacement than a 3rd gen SBC
- Instead of PCV, used a "road draft" tube at the back of the lifter valley by the distributor
- If factory '57-'59 heads, different valve cover bolt pattern than '59-1/2 to '86 perimeter bolt valve covers with no oil fill or PCV holes available (oil fill was at the front of the intake manifold until '68, I believe it was - last 283 was '67)
- If factory heads, there's about a 99% chance that they are small valve and poorer flowing than 3rd gen era SBC heads (including swirl ports)

This is one of those "Yes, it can be done" things. The real question is, why in the world would you even consider it? If the answer is, "Because I have it," or, "Because I can get one cheap," you're starting off on the wrong foot. You'd be better off getting a later engine.

 

Good information. I didn't know anything about the 283CID engines myself. I was wondering why the hell anyone would want to install one in a 3rd generation Firebird or Camaro.

 

The original 283 in the '57 was one of the first engines I worked on.

The '57 283 was unique in that it didn't have side engine mounts (the '55-'56 SBC's didn't, either, but a 283 wasn't available until '57).

Now that I think about it, the early SBC's had rope rear main seal instead of 2-piece neoprene. Didn't change the flywheel mount to the crank, though.

 

my friend wanted to put one in his cause he blew up the 305 and asked me what you would have to do. me personaly i like the 350 best but thanks for all the info!

 

The 350 is the way to go. They are cheap and plentiful. If you can find a 305 with low miles on it, then that's not a bad way to go given how cheap you can get those for. However, I wouldn't use that as the basis of a performance build.

 

Another difference: '62-earlier blocks weren't drilled for block-mounted starters that are compatible with aluminum transmission.

Sell the 283 to someone restoring a period-correct car. Stick to later stuff ('69-up) for installation into 3rd gens.