5.3 or 454

[Crow402]

Im thinking of doing one or the other of these swaps. What is your guys experience with them? Also which one would you choose? What are ones benefits over the other? Thanks in advance.

[Liberty]

Originally Posted by Crow402

Im thinking of doing one or the other of these swaps. What is your guys experience with them? Also which one would you choose? What are ones benefits over the other? Thanks in advance.

While I LOVE The Hugeness of the 454, you'll probably get more performance out of the 5.3, fuel economy will be vastly superior especially with the fuel injection.

However the 5.3 would be harder to swap in than the 454.

[andrewmp6]

To me depends how you use your truck.If its a driver go 5.3 if its a weekend toy or something that will pull a lot of weight go big block.

[nonstop]

Went from 350 to 454. In total, cost about $6k with the rebuild and chasing brackets and all the small parts. That was with a chassis those came in! I couldn't tell you the cost of a 5.3 swap. I am VERY HAPPY with the 454 though! I built it for torque, and it has a load of it on tap! You do need to go into it though with the understanding fuel economy is not a concern and any you get is icing on the cake!

We had a Tahoe with the 5.3 and drivability was nice! Good power too! Mileage was pretty good as well! I am just a sucker for a big block!

[Bigstevex4]

Seems like a choice between 2 completely different options What do you have to put it in? transmission? Rear end gearing?

[77c10]

There's no replacement for displacement.........

[Crow402]

Originally Posted by Bigstevex4

Seems like a choice between 2 completely different options What do you have to put it in? transmission? Rear end gearing?

It's a '80 c10 shortbed stock rear and a th350. I want power but I'm not looking for crazy power 400-500 range is fine. It also comes down to time because I'm joining the service soon.

[nonstop]

Either will probably require a transmission swap either to hold up to the power of get the most out of the 5.3. Since time is now a concern, I would probably go 454 since it is bolt in and requires no fab. Whichever swap you do, it might be easiest to buy a donor truck and scrap the rest.

[Bigstevex4]

A 350 or 383 would be my choice a BB cost just about twice to build, still not sure what Eng have now. the trans would be just fine. and cost about half what either the other 2 would. Again that's me. I dam near bought a 396 guy had built sold the car. Going with a350 to replace 6 cyl.

[Crow402]

Originally Posted by Bigstevex4

A 350 or 383 would be my choice a BB cost just about twice to build, still not sure what Eng have now. the trans would be just fine. and cost about half what either the other 2 would. Again that's me. I dam near bought a 396 guy had built sold the car. Going with a350 to replace 6 cyl.

Yea it has a 350 now from a 73 pickup. I like 350 and 383s, but here in Nebraska that's a really common swap. So I would like to do something different.

[crashz]

I swapped a 454 into my 83, which also has a TH350. Towed a lot with it, even with a lift and 35 inch tires. One time I had a 1 ton roller in the back, while towing a 5 ton roller on a trailer. The BB was great. A gas guzzling pig too. With a Quadrajet, it would average 6-8 mpg. I mistakenly swapped a Holley on there and mpgs got much worse.

If you can do it, I think the LS is a hot ticket. Daily its more common (like a Cummins swap), but its just a great engine. And will make a very fun driver. A full swap from a donor truck with transmission is the best set up. Might be the most cost effective as well.

[bigblock73]

454 for ease if install and to make a statement and sound good, LS for mileage and modern performance

If you go BB, you could always add aftermarket EFI down the road...

[Crow402]

Thanks for all the input everyone

[andrewmp6]

Or be different swap in a caddy big block or a diesel.With these trucks just about any engine will fit.

[LSX408]

I would go with the 5.3. It will easily meet your power goals with good drivability and economy too. Plus they are super tough!

[burb1085]

I'm about to swap the 454 t.b.i./Th400 from my 87 R20 Suburban into my 85 305/th350 short bed. Probably will use the stiffer R20 3/4 ton springs, to help balance it out. I've heard just a cam swap and exhaust headers will bring power up allot (can't remember how much, but there is all kinds of info on internet about how to hop this block up on a budget). The price for heads for big blocks is crazy, and one of the most expensive part upgrades. Mileage with the t.b.i. still isn't great, but you get a few more than with a carb. You also have to remember you can't have both power and good mileage with a bbc, it's a compromise. If yo want good mileage and good power go with the LS. Wonder who on here has had both engines in their truck, and which engine they prefer. I would be interested to know.

[Tom]

Unless your towing and need alot of internal mass swinging around to create torque, OR you want the biggest, baddest NA engine around, then I don't see the point of a big block anymore.