Hi everyone!

I own a 1987 240 gl, euro edition with a B230K engine, automatic here in the Philippines. I have the following concerns which I hope you can help me out:

1. I bought the brick minus the "Heron" cylinder head (casting number stamped on the side of the head is 1000631 and found a spare head for a 240 with casting number 1000530. I used this head instead.

2. The flame trap, EGR and Pulse Air System has been removed already and all tubings and hoses related to the EGR, PAS and flame trap has been sealed. Including the pipe coming from under the exhaust manifold near the fire wall and the pipe directly under the intake manifold.

3. The Solex Cisac carburetor has been overhauled already, with new gaskets in between the carburetor spacer. New air, fuel and oil filters changed, used Mobile One synthetic oil.

My problem is poor acceleration and an occasional and slight backfiring. At high speed starting at 70 kph, engine runs smoothly. Problem comes back during decceleration. I think the culprit is the incompatible cylinder head. Your inputs will be highly appreciated.