Thornton SBC Headers



New Thornton shorty header design for Small Block Chevys. Thornton style headers are designed for easy fit without the hassle of exhaust leaks.
These headers were designed from 1969 Camaro cast iron GM manifolds 3942529 and 3932376 and are a stock replacement for factory manifolds.
They will A, F, G and X body bodies, Chevelle, Camaro, Z28, Nova, Malibu, El Camino, 4 speed and automatic cars with or without air conditioning.

  • These headers will fit in the same cavity as factory exhaust manifolds. JUST USE BIG BLOCK 2.5" DOWNTUBES TO CONNECT TO YOUR EXHAUST!
  • PYPES Big Block Downtubes- DGU20S
  • FLOWMASTER Big Block Downtubes- 81071
  • No need to move brake lines.
  • Mini starter is not needed. 1 5/8” primary tubes, 3” collector with factory fit 2 ½ exit flange (same as big block) with stock style exit flange and fits standard stock big block down pipe.
  • They work with factory heat riser valve.
  • They work with air conditioning and power steering alternator.
  • Stock style exit flange with 3 bolt design with donut for no leak design. They use stock big block down pipes.
  • Thick, flat flange at cylinder head that will not warp, no leaks.
  • They are designed to fit in tight spaces, same as the stock manifolds.
  • Exit flange is located in same spot as the original but with a much larger design.

Watch the video for installation instructions!

A short spark plug is needed, this is common for headers.

The only minor modifications needed are on A/C and P/S brackets, and a slight dimple may be needed on the #3 tube for the #7 plug.