I am at a crossroads here. I bought a new GM Vortec 350 crate motor a few years ago and have only put about 6,000 miles on it. I was thinking about installing the LT4 Hot Cam, with all of the necessary head mods, and calling it a day. It already has all of the bolt-ons added.....New Edelbrock 600 carb, Hedmann Long Tube headers, true dual exhaust, HEI, Air Gap intake.

Now, I also have a 1993 454 on an engine stand. Yes, it has the dreaded "Peanut Port" heads. It can be made to make good power if cammed correctly. It is a virgin engine. Standard crank and bore.

My trans is a built TH350 with a 2,000 stall.

The car is my daily when the weather is nice. I do want to do the Power Tour someday.

 

 

Buddy of mine put a 454 into his Impala. It came out right after and had to go to the machine shop to fix the previous builder's mistakes. In the end it cost a ton of $$$ and ended up with a Vortec 350 that he likes better.

 

Back in the day---before the advent of the LS engines---a big-block/3rd gen swap was somewhat popular. Today though, it's just not worth the work, expense, and problems considering the relative ease and streetable power output of the aforementioned LS options. Even a relatively mild 6.2 will produce 500+ very reliable, no-overheating horsepower, a level at which your 454 would be near it's ragged edge for everyday driving. Additionally, as already mentioned, that big block weighs like a boat anchor compared to an aluminum LS, and would negatively affect handing and braking.

If you can't get the level of performance you want out of your small block, look at an LS swap, something that has been documented many times in the car mags, and has a vast amount of support on this site.

IMO, it's an easy decision.

 

I would agree that weight is the deciding factor here as all of the swap components are readily available. There's a 502 BBC crate engine in the 86 TA "fleet" car and other than the 4" cowl hood needed and the ridiculous Hooker Pro Comp headers (and an oil filter adapter for the remote filter that keeps weeping) it fits like factory.
On the subject of weight I can across these little tidbits:

BBC vs SBC comparison (all without accessories):
Iron 327 SBC with aluminum heads and intake. 435 pounds.
509 BBC (Merlin) with iron block and iron heads, and aluminum intake. 640 pounds.
509 BBC (Merlin) with iron block and aluminum heads, and aluminum intake. 555 pounds.

So, there's about 120 lbs in the difference.
As for HP output, if you can't make 600 no sweat CHP out of 509 CI, then you're doing something wrong. The 502 mentioned above has 502 HP/502 TQ right out of the crate and a cam change has been verified to add another 75 HP. All below 6000 RPM.
Now having said that, I'll counter my first statement by saying fitment is somewhat of an issue. It's pretty tight and as mentioned, the headers are ridiculous (although I understand that some of the more specialized manufacturers like Lemons or Kooks have a better offering but I can't say I've really researched that).
As for the OP's options. I can attest to a Vortec 350 making better than 425 CHP with a properly spec'd cam (not the Hot Cam or any other OEM offering though), an Air Gap intake and a suitable compression ratio.
The 454, even with the smallish heads can surely muster 1 HP/CI with a properly spec'd cam (there's that phrase again: properly spec'd). So the horsepower outcome is pretty much a wash. Now throw some decent heads on the BBC, then you're into significant gains vs the stockers. More than enough to make up the weight penalty.

No regrets but if I had to make that decision today, I would probably pass.

 

Anyone else?

I'm trying to make up my mind. Lol.

 

why not a 400 or 455? You have a Pontiac, right?

 

LiquidBlue, I have thought about that. They seem to be really hard to find. I live in SW Oklahoma and almost every old Chevy/GM 3/4 ton farm pickup has a 454. Very easy to find. What I would like to find is a 1996-2000 Vortec 454. They have factory roller cams.

 

As far as a daily driver you can do anything and everything you would ever want with that smallblock. Big-blocks are heavy pigs meant for old heavy muscle cars and work trucks. Yes they have tons of torque and some people think they are great just not a good fit for a 3400 lb car with a mickey mouse rear end. My Dad always loved them in his show cars, but his drag cars always had small blocks.

 

those things are like 7.8 to 1 compression lol. It would need pistons and better heads to make worthwhile power. By that i mean 550-600+, where you cant get that easily wth a oem block 350-383. If you only make 400-450 hp you can do that with a 350-383. Without the size and weight. Peanut Heads can be ported tho but can be pricey since they are iron. I wouldnt want all iron bbc in my car

 

Yeah once...

Shoulda made it a 502.

 

im not normally on the "Ls" band wagon. an sbc can easily make all the power you want without to much fret. its all been done before and all of the parts are readily available. I would call the big block a turd in a car like this. I would vote for a crate engine from blueprint or a similar company. they are putting out 400-460hp motors with torque to match or beat any big block. you can also go Ls. those motors are proven to be everything a hotrodder could want. the issue I have with "installing" an LS is that it requires so much work that its called a conversion. ive been looking at a blueprint 355 sbc with 375hp and 400lb/ft for my replacement. that's more power than I will ever need in my daily driver. gonna be a hoot..

 

I believe that all of the above comments are valid. SBC has its advantages, as does the LS, but then so does the BBC. They ALL can be made to do pretty much anything you want. So you gotta ask yourself, what do YOU want it to do. Whatever you decide, just make it Yours.

 

Thanks for the replies.