school me on 454 swaps

[1low4x4]

Hello fellas...I got some leads on a few 454's for sale...and I was wondering what all id need to swap in place of my 350. Motor mounts? What about accessory brackets? Will my current ac compressor and power steering assemblies work on a big block? Will a stock 454 yield better power than my rebuilt 350, enough to justofy they trouble? Or should I build one up with a bigger cam e tc? Any info is appreciated!

 

[1low4x4]

Also will my current long tube header setup work?

 

[Green79Scottsdale]

Header question is easy, no your headers will not work, but from there back you can use the existing system.

The swap question is going to garner many differing opinions.

Question for you.... Why are you thinking about this swap in the first place?

 

[1low4x4]

Because the 350 isnt powerful enoigh to pull the boat!

 

[foamypirate]

Because the 350 isnt powerful enoigh to pull the boat!

What rear gears are you running? I'd almost think about a gear swap before a 454 swap, especially since you are running a 4L80E.

 

[Jims86]

None of your current stuff, save for the exhaust from the collectors back.
I personally would go for gears, then a better top end build, before shticking A BB in.

 

[bucket]

I'm putting a stock 454 in my Burb for better pulling power over a 350. Even though a stock tbi 454 is no powerhouse, it's still got a lot more balls than a 350. Your stock mounts will work, but for the most part everything else is different. Some things can be reused, but a lot depends on what model year parts you are playing with.

 

[Green79Scottsdale]

The two things I would look at initially are your gears as stated, and also the cam in your current motor. With your overdrive I bet you could go to even a 4.56 gear and be good. If you don't want to go that deep, I say 4.10 and re-evaluate the situation. If it still isn't up to your liking, then look at the cam specs and see if/how you can improve that. A cam swap would be more realistic, to me at least, instead of a motor family change.

 

[Driver4r]

The two things I would look at initially are your gears as stated, and also the cam in your current motor. With your overdrive I bet you could go to even a 4.56 gear and be good. If you don't want to go that deep, I say 4.10 and re-evaluate the situation. If it still isn't up to your liking, then look at the cam specs and see if/how you can improve that. A cam swap would be more realistic, to me at least, instead of a motor family change.

Pretty sure i read somewere that he has 4.10s.

 

[El Camino Man]

You can build up a 350 to be a stout runner for pretty cheap. Some good heads are a good investment.

Since you have an OD tranny, then 4.56s might not be too bad. Just don't take it on the interstate lol

Going from a 350 to 454 is a whole other ball game from what Iv read. Yes they've got a ton of grunt down low, but once you get it wound up on the highway, Im sure power will be similar. Not to mention you will be going from probably 14ish mpg to 10 is whats holding me back

 

[1low4x4]

It has 4.10s already. Its not strong enough to hold 65 in 4th gear. I have to shift into third. 4L80e I can pull in OD but the motor isnt strong enough. I think the quadrajet isnt helping I think my uncle set it up for a 305 not a 350. Cam is stock.

I have another carb thats supposedly set up better its a quad also. What size cam should I change to. Provide a link and ill buy it

 

[El Camino Man]

But if you overfuel it, youll have the same problem too lol.

I think a nice cam would do wonders in your engine. Id put one with a bit of lope on it just for fun lol. It suuuure couldn't hurt!

 

[Jims86]

Because the 350 isnt powerful enoigh to pull the boat!

Whoa whoa whoa whoa.....wait a minute. It did the job before. Do you mean not powerful enough to pull the boat faster?

 

[bucket]

You can build up a 350 to be a stout runner for pretty cheap. Some good heads are a good investment.

Since you have an OD tranny, then 4.56s might not be too bad. Just don't take it on the interstate lol

Going from a 350 to 454 is a whole other ball game from what Iv read. Yes they've got a ton of grunt down low, but once you get it wound up on the highway, Im sure power will be similar. Not to mention you will be going from probably 14ish mpg to 10 is whats holding me back

Comparing them stock to stock, a 454 will out pull a 350 in ANY occasion. Low, mid, or high. For me, difference in MPG has been negligible.

 

[Driver4r]

Comparing them stock to stock, a 454 will out pull a 350 in ANY occasion. Low, mid, or high. For me, difference in MPG has been negligible.

The 350 will wind up a hell of alot faster.
Yes a Big Block Has more Grunt, but with how much added weight 300lbs roughly.
Its not worth the added weight for the little grunt you would gain. A stout Smallblock will run circles around a bigblock.
Alot of times when people go bigblock for the power, is cause they need the extra block so they can bore out farther then a small block will take.