With the stock heads on it ? Or is it similar to say, a Vortec , where it doesn't work without modifying things ? To make sure noone gets confused ,this is on my 1992 Firebird with a 305 with stock heads . It has a TBI now , that I am going to upgrade to MPFI .

 

Will it fit?

Yes and no - hows that for a straight answer?

... but the reason I say that is this: The LT1 manifold has the same bolt pattern and port locations as your 305, so in that sense it will bolt up and fit.

The problem is with the coolant crossover at the front and the distributor hole at the back - they aren't there. The coolant crossover/thermostat housing boss wasn't needed on the LT1 because that stuff was located on the water pump, and the distributor hole is not drilled out (though I think the spot was cast into the manifold?) because the distributor is on the front timing cover on the LT1.

The LT1 manifold can be modified to work with a traditional small block engine like yours, but I don't know the specifics myself, as I never tried, but there should be a ton of info on this in the 'TPI/EFI' board, as its a pretty common swap to do from what I hear.

(My DD is a '97 Z28 w/ LT1 and my 3rdgen is a carbureted 357ci, so I know some about both engines, but never mixed and matched between the two like what you are asking about).

 

Dude you are gonna have to take a look at the whole motor if you want your parts to run right with a 305 TBI. Those heads the way they are won't flow well enough for what you're thinking of doing.

 

Air Adam, I don't remember any spot for a dizzy hole to be drilled out. The underside at least doesn't have a spot...

 

I was sure there was a circle cast on the topside of the intake where the machining would normally be done, that was never eventially used on the LT1 - I'm a little fuzzy on that one though, been awhile since I looked at an LT1 manifold, but I thought I remembered it being there?

 

I can't remember there being one on the top side, I'll have a look at the two LT1 intakes I have.

 

I thought LT1s used an optispark?

 

So much bad info in this thread

Read:
http://www.lt1intake.com/files/faq.html

To convert:
Middle 6 intake bolts on each side must be filled and redrilled. 4 corner bolts line up correctly
Distributor hole must be aligned and cut
Platform for the dist must be assembled or an angled spacer installed
Coolant crossovers must have material added or will leak coolant
EGR port must be covered in multiple locations or gasket will not seal
Coolant bungs must be added to the front or rear crossover and routed to a remote thermostat and housing
LT1 EGR must be removed and blocked off or the entire area cut off and welded shut
For manual cars any LT1 throttle bracket may be used
For detent (cable) automatics (700R4 and 4L60, not 4L60E) a 93 LT1 bracket must be used and modified


Stock heads will work fine, they are not the best performance wise but function, they will
Vortec heads will not work, refer to the link above for why
TBI to TPI will be the biggest hurdle, are you sure you are ready for that?

There is no boss cast into the manifold

Alternative port EFI forum
Not very common, most people prefer to buy and install rather than modify to maybe use

They do, it has nothing to do with the intake thou

https://www.thirdgen.org/forums/engi...d-replace.html

 

I'll have to confess I've never understood this swap.

A Stealth Ram will run you $320.

 

Pocket wrote =TBI to TPI will be the biggest hurdle, are you sure you are ready for that?

My friend Tim does the TBI to MPFI swap for me . He did it in my old 406 powered vert . He is a great tuner too ,so I got that covered too .

five7kid wrote = I've never understood this swap a HSR will run you $320.

First of all , I am only paying $100 for intake injectors and throttle body . And the $320 for HSR will get you the intake only . No runners . No throttle body . With runners 609.95 . Still no throttle body . And to anyone else wondering , if I do this it isn't just for the 305 . I have a 406 short block on a stand in my garage . I have already read all the stuff on LT1intake .com now . And after reading , I am having some 2nd thoughts on it . May or may not do it now . If not Tim wants it for 1 of his cars . I forgot that my brother had my old Torker II intake and TBI adapter , so I went today and got that from him today . Maybe that will appease my need for modding for the moment . Then I can save for a HSR , which I would rather have , in a perfect world