carb adapter needed??

[Crash520]

Guys, I have a stock '73 340 with the original thermoquad, Im fitting a FAST EFI TBI unit to it which has a Holley 4150 pattern, do you know if the manifold has a dual bolt pattern or will I need an adapter and if so which adapter does anyone know please.

[Shane Kelley]

It won't have a dual pattern. There are adapters out there but honestly you would be better to replace the intake. What you have is called a spreadbore intake. You need a square bore. Early 340's use those. 68-70 model years. Check with Summit Racing if you choose the adapter route. They probably sell them or just order yourself a new Edlebrock aluminum intake and do it right. You will save weight and might even get a small power gain. Edlebrock Performer Rpm or Rpm Air Gap would be some nice choices. The old Edlebrock LD4B works great but you would have the track one down.

[Crash520]

Thanks Shane,
Its only a temp solution, I'm installing the EFI on the stock motor as I know how that motor runs so i want to do initial set up on it, Im building a 408 that the EFI will eventually fitted to, the 408 is a W2 motor with a Victor manifold, thats the ultimate end goal for the EFI,

Greg

[Shane Kelley]

Thanks Shane,
Its only a temp solution, I'm installing the EFI on the stock motor as I know how that motor runs so i want to do initial set up on it, Im building a 408 that the EFI will eventually fitted to, the 408 is a W2 motor with a Victor manifold, thats the ultimate end goal for the EFI,

Greg

Nice!
It seems like I have had one of those adapters around here somewhere. If you can't find one PM me and I will see if I can find it. That will be the issue.

[Crash520]

Thanks Mate, appreciate it, I'm in Australia, I just purchased one of Fleebay, paid a fortune for them out here but thats life.

[RUNCHARGER]

Aw jeez: I could have sent you one as well.