I have an 82 z28 and i am puting in a 72 402 in it i need some exhaust ideas asap

 

putting in a 400 series big block is stupid. Buy a 400 series small block and save yourself a lot of weight off the front end. Or buy a 454, they're pretty cheap. In anycase buy hooker big block headers and run duals

 

Have you read the sticky about bbc swaps at the top of the engine swap section yet?

Personally, I would make some clearance for the manifolds first. That's what I did with my Buick/Olds swaps. You can make custom headers later; you need to get the beast functional with a BBC first.

That's just my opinion, no flames. I do unorthodox swaps. I ALWAYS MAKE THE MANIFOLDS FIT FIRST.

Good luck!

 

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Oh, and don't listen to the flames about being stupid. Those guys don't like anything except chevy small blocks...

A 402 is as good a place as any to start your big block swap. You can always dump in the built 454 or 502 later on when the budget allows for it.

Good luck!

 

Me, personally, I like performance... Why would you ever buy those manifolds.

I am a big block fan, but only when it actually makes sense. There is no point to dumping that much weight on the front end for no reason. I'd rather have a 350 with a cam then dump a stock 402 in my car.

 

There are plenty of "performance" engines out there with manifolds on them.

You obviously don't do alot of engine swaps.

The "point" comes in one of two forms:

1. NOT wanting to be the same as everyone else

2. Using what you have (budget reasons)

You can get springs to hold big block weight in the front. You can also set up the car to use it. Many other Camaros have done this before ours were in production with similar front to rear weight bias. You can run aluminum parts that lighten it up as well. All that comes later...

First comes making it fit properly so that it's not a hack job. If your only big block swap experience is in 70s or older cars with engine bays like a Kenworth then you don't really understand the fun in making the swap work. Swapping or running a big block in an older, bigger car is the same as swapping a small block. It falls onto the motor mounts and bolts to the transmission like a 350.

Oh, and nobody said that YOU should dump a stock 402 in YOUR car. He is asking for help in getting his in.

He just wanted help with the exhaust...

 

First thank you for all advise. Second it is a far cry from being stock. Yes this is my first swap for a bb so I am learning as I go. I will be satisfied when all the people who said it is stupid or wont work see me prove them wrong.

 

I'm running the baby big block in the '57 because that's what I had at the time, and don't have the funds at this time to do anything different. 400 RWHP isn't anything to sneeze at, IMO. Could you do that with a SBC? Of course. But, probably not for the money I've got in this 396.

One big advantage of the BBC over SBC is the heads. Great flow for little work or money. Pretty easy to make up that 100 lb penalty.

One disadvantage is the exhaust. A bit harder to route. But, listen to all the problems people have with SBC long tubes, and it isn't so bad anymore.

Check the BBC sticky for the link to the exhaust thread. Used Patriot headers, slight modification to the engine mount and firewall. No biggie.

 

thanks for your view on me, no one cares

And yes I did post to help his exhaust problem out maybe he should search before posting

 

 

Externally there's no difference in size between a short deck BBC from a 396 to a 540. Unfortunately, doing a BBC swap into a third gen always creates a few headaches. The exhaust system is probably the worst. You can cheap out and use factory exhaust manifolds but you really restrict the exhaust and any performance. The Hooker Supercomp swap headers are the cheapest swap headers, they're the worst fitting and with only 1-7/8" primary tubes, they're not much more than a good street header.

As with any BBC swap, you can go from mild to wild with what you want to do. An engine can be so completely stock that it can't outperform a hopped up 350 or can be a real monster.

My race engine has Ed Quay headers. 2-1/4" primaries with 4" collectors. The headers are worth over $1000.

Here's the 540 under my hood or at least how it look at the end of the 2007 race season. I'm going injected alcohol next year with a dual toilet system.

 

I have seen guys run the manifolds and make tons of power. Can't you port the heck out of them for the flow that you want? I've seen Buick guys do this, but I admit that I don't know how much meat the BBC manifolds have in there for removal...

 

First of all you need to find a set that are not cracked. They're very common to crack in the center. Trying to find a set of BBC car manifolds may cost more than a set of headers.

Here's a typical late model BBC truck exhaust manifold.



Here's a typical BBC car manifold. Both styles are very restrictive and heavy.



Because of how the chassis is shaped on a third gen, using late model truck manifolds as a cheap alternative providing you can get the cheap, will probably offer a better fit for the exhaust pipes although both styles will probably work.

 

One of the members here used 8100 V8 avalache tubular manifolds in his swap, looked liked they worked well to me.