MSefi.com read only forum (Jan.15,2018)

I'm building a 455 Pontiac with MS. The intake manifold is the Tomahawk, which has the injector bosses above the intakes, but no holes machined in, it's just flush.

I've dropped the top end off at the engine builder and he needs to know how to machine for the injectors.

I expect 525 HP and figure that I need 42# injectors. I was figuring some standard Bosch 42# injectors. Does anyone know the part #? There seems to be different kinds, etc. and I'm not sure of the nuances between them.

What injectors would anyone recommend (including part # please), and what is the required machining on the intake where they have left a machined flush blank spot? If I recall, someone else had used 42# bosch injectors on this manifold & only had to machine 14mm holes without any countersink. Do some injectors require a counter sink & some no?

Thanks,
Scott.

Stan-

Thank you for the reply.

I'll take a look at the resources that you shared, & prob give Ross a call this week with some of my questions.

However, you indicated that 'if I had enough material', I could get the tool from Ross. Yes, the intake manufacturer molded bungs in with a machined flush surface on top, but no hole. So, do you mean that there is a special jig to use to put the hole in? Why not just machine a straight through hole for the o-ring? Is there actually supposed to be a counter sink necessary with sort of a stepped hole with 2 sizes?

Thanks,
Scott.

Thanks ALAN. Duh... not sure why I typed Stan in my first reply!!

Your links were helpful.

Cheers,

Scott.

Would the LS1 injectors that I'm considering require the same machining to the intake that a stock Buick setup would have?

My machinist does Buick EFI setups and has them as an example. I'm going to purchase the injectors and bring them into him, but I think it would help if he knew it was the same as Buick.

Thanks,
Scott.