I am starting to plan my next build wich will definately be a BBC. I did a few searches and it seems that most people tend to stay away from tall decks due to headers clearance. My car already has a tubular k-member so I was if that would make it doable. I understand that it will need a set of custom headers but so would a 540ci+ short deck. My theory is that a 632 shouldnt be that much more work, maybe some more $$$ but nothing to crazy over building a 540.

 

Tubular k-member isn't the issue with a tall deck. Heater box and brake booster may be.

My 540 is a short deck block but my heads have raised exhaust ports as do most good aftermarket heads. This raises the header position even higher. I run Ed Quay headers. They have 2-1/4" primaries into 4" slip on collectors and clearance is very limited. I have a couple of tubes dimpled for clearance around tubular suspension components. The header flange is cut between the tubes and the tubes are installed like a jigsaw puzzle before the collector is finally installed.

Using a tall deck block and having heads with raised exhaust ports puts the header position even higher. This means custom built headers will be needed as the collectors need to be lower to stay under the floor. There's only so much room to lower the engine and the front "frame rails" taper inward behind the engine limiting how much it can be moved back. Unless you have some good fabrication skills, I wouldn't be surprised if a set of custom built large tube headers to work with a 632 will set you back around $2000.

 

How much did your Ed Quay headers cost?

 

You will clear the brake booster but need to pull the heater box and wiper motor.

 

I already removed the wipers, and heater. How much clearance is there for the brake biister?

 

I bought my Ed Quay headers used and got a smoking deal at around $500. New they're somewhere in the $1000-$1200 range, possibly higher but that was many years ago. The cost has probably gone up. www.edquay.com

The tubes were also coated but the collectors were not. Coated headers really help keep the heat out of the engine compartment and is really worth the investment.

www.lemonsheaders.com doesn't have a listing for a third gen BBC but do list many others. All their headers are $1200 for a set.