I was just wondering what the biggest possible engine that would fit into my 91 firebird? Is an LT1 about as big as i can get? I currently have a v6 and really want an upgrade.

 

Any size SBC will fit with no problems. Externally, they're all the same size.

Up to a 540 BBC will fit with little to no modifications.

 

what would you recommend to put in? i really dont know to much about engine sizes

 

A 350 is basic and the most common. A 383 is the most popular increase after that.

 

Buick 3.8

 

what do you think about a 454?

 

Over-rated. (in stock form)

If you're gonna go through the hassle and expense of a big block, go with a big one, 502 or larger.

 

I'm finishing up my 3.1L to 454 swap. Wasn't that tough aside from the exhaust. If you have the money get some headers designed for the swap and everything will go well.

 

What is your budget?

 

I would like to keep it to $5000 for everything, but if i need to i will spend more. I plan on getting used/rebuild engine and transmission. Then im going to look for the rear end and everything else out of a wrecked car, this site, or possibly ebay.

 

There is nothing different about your current rear end and one you would get off of a junkyard car, this forum, or eBay, except perhaps posi. Your V6 rear is just as strong as a V8 rear, and neither are strong enough for a 454. An aftermarket rear that is strong enough will run about $2k, and that won't have brakes.

My rule of thumb is plan on spending as much handling the power as you do making it. If your total budget is $5000, then you have about $2500 to spend on an engine. Regardless of what you put in, you will need totally new exhaust and some chassis upgrades. Big block exhaust (a 454 is a big block) is about 50% to 100% more expensive than small block exhaust (350, 383, etc.). Sub frame connectors should be considered a must. You will need a different transmission, as your V6 transmission will not mount to a V8, and would be too weak if it would (you appear to know you need a different transmission).

A 350 swap would probably make more sense, based on what I see in this thread.

 

What about an LT1 motor? I was originaly thinking that. I have been offered one for $500.

 

What year?

If it has all the harness and the PCM, basically everything that's needed to run, it's a great choice. See the LT1 sticky in the top section of this or the LTx and LSx Engine Swap subforum.

It is more involved than a Gen I 350 swap, but probably no more than a big block Chevy swap.

 

I disagree. A 10-bolt 26spline is weaker than a 28spline. And if he could find a borg warner axle that would be even better. And as long as you don't actually get traction a 454 won't break a 10-bolt any more than a 350 will.

I'd recommend an LT1 swap as well. Lots of power, reliability, and a more direct bolt in. Aside from the wiring.

 

His is a '91, which is 28-spline.

 

it is a complete all stock LT1 motor out of a 93Z28 with approx 89K miles on it

 

If it had an automatic transmission behind it, it will be compatible with 3rd gen V8 automatics.

Doesn't sound like a bad deal, but you need to read the LT1 sticky information before you jump in.

 

could you post the link to it

 

Well, it's right in the top section of this forum, "Common LT1 Swap Questions and Answers".

 

ok, thanks...i will look through it but i dont think it will change my mind about doing a swap. just from glimpsing at it, it looks like some good info.

 

y not just build up a 350 with some strong heads and intake, th350 and a 3500 stall with some 3.42 gears. will be for a strong runner. will def. run with some ls cars.

 

I realize that this is beyond your budget, but I wanted to put it out there that the normally aspirated engine in the link below makes 900 HP @ 6200 RPM and 845 TQ @ 4600 RPM, plus it runs on pump gas.
http://www.ultrastreet.net/engines/632_bigdawg.asp

 

that is sweet, i wish i could afford that

 

if your just looking for a monster engine i personally would say just take your time and do it right, if your gona do it right your gona spend more then 5k(well unless you do the work yourselve like alot of us on here prefer) i would say go with gm performance parts lsx block. it has a max displacement of 520ci and is a small block, all the ls series parts fit it and you can go up to like 2500hp with it if you ever decide you want that much(or it will run forever at a lower hp rating) the only downside is it has a rather high pricetag to start roughly 3k but tbh thats about what you spend on any after market block if you every plan on going over 500hp with a small block or 700 with a big block(yah i know people run stock blocks with more but some of them also run less and have em bust those seems to be the generally accepted safe power levels) plus you get better intake and cylinder head designs with a better cooling system

 

You're absolutely going to spend more than $5K. Big blocks are expensive. And the rest of the car isn't designed to handle the power. Basically everything from engine back will be replaced. The frame will have to be braced. Suspension will need changes. Custom headers and exhaust. Then you need bigger brakes to haul down all that extra weight and speed. (V6 rotors don't cut it) I would budget $15K+ to get a reliable car with big power - and that's not including the car itself.

 

thanks for the info and advice