First Time offered.   New, superior design Thornton Reproductions header. Custom Fitted small block Oldsmobile.  

This is our first run so we have limited sets in stock.

Not to be confused with our other small block headers, this set is improved for better fit and function by using 304 stainless, thicker flange and  tig welded

Brand new Thornton design for that factory fit small block Oldsmobile tubular header made with a natural 304 stainless steel finish with a 1/2" thick stainless steel flange to prevent warping.  Tig welded.

We are very familiar with Oldsmobiles and we can help with your fitment questions and and issues/problems/questions you might have so please ask us how we can help!!

This is high quality heavy weight 304 polished stainless 

As shown in the picture, the second pipe on the drivers side has been flattened to allow for frame clearance and this is not visible when mounted on the car.

Pictures posted on this listing were our original sample on a 1970 W31 and test fitting the actual finished polished headers on a 1967 Cutlass.

Also available ceramic coated , look for our eBay listings 

This is very universal fit.  If you can fit factory exhaust manifolds these headers will fit with out any modifications. factory fit for 4 speed manual transmissions. standard  exhaust head pipe 2 1/4" or 2 1/2". primary tubes are 1 5/8" with 3" collector.
Sold with a pair with gaskets


Any questions will be answered



Headers are made of stainless and weigh 20 pounds.  Stock cast iron exhaust manifolds weigh 40 pounds.

These headers are fitted to replace your factory exhaust manifolds with tubular headers with no modifications needed.  There are no issues with clearance with the starter, frame, Z-bar, dip stick, steering shaft,  etc.  All accessories will fit without modifications; all air conditioning, power steering, alternator brackets all attach to the engine as original . Fitted with stock 4 speed equipment. 

We have test fitted to 1967 Cutlass 330, automatic, power steering and air conditioning. Great clearance to the steering shaft. Transmission lines have good clearance.  Power steering bracket bolted as original manifolds. The 1964, 65, 66 and 67 are the toughest to fit headers on and we custom fitted and produced so it is as easy to fit as possible. Best to be installed by professional. On the 67 we removed steering column. Unbolted one motor mount at a time and jacked up engine so the header slides into position to be bolted up. The driver side header you will need to come down from the top to go over your factory dip stick tube. The flange on the headers have the same dome shape as the cast iron exhaust manifolds so stock exhaust will attach to the headers with no sweat. The stock rusted exhaust that was on the 67 test fit car pushed up into position with perfect fit. 

These headers will only fit small block Oldsmobiles with 260, 307, 330, 350 and 403 ci. engines.  

These headers will fit all A body cars plus the G and F body cars equipped with a small block Oldsmobile.

These headers will Not fit 1965-1970 B&C body Oldsmobiles. Delta 88,98 and Starfires from 1965 to 1970 had a rear mounted steering box toward firewall and steering box is just below rear cylinder on driver side. We have no headers for that design. 

 If you have special / custom that you are installing small block Oldsmobile in give us a call for fitment.

The exhaust outlet is best fitted to 2 1/2" head pipes with factory style flair and will fit 2 1/4" standard head pipes.  Flowmaster and Pypes exhaust will fit perfect with their standard down pipe for the small block Oldsmobile.

Special torque sequence is needed.....do not tighten top center bolt until the other 4 bolts are tight, 25 pounds, start at the center 2 bolts then the 2 outer bolts then the center top bolt last


Please feel free to ask questions before purchasing.  We stand behind all of our parts we sell on eBay so returns are not a problem.  Your satisfaction is guarantee

We also offer multiple small block and big block Oldsmobile headers and manifolds,  LOOK FOR OUR LISTINGS ON EBAY

Thornton Muscle Cars
832 Mine Rd
Quakertown, PA 18951

Due to supply chain demands and issues some items such as hardware, color etc may vary