Opinions on best build with these parts.
 

I got impatient and purchased a running 1974 400, 4x heads and turbo 400 tranny. Trying to decide what my final build will be with my available parts before I sell anything. I have a complete '75 400 engine, 5C/6X heads and HEI. I also have a disassembled 1970 350 with 11 heads, Edelbrock Performer intake and a Holley 650 carb.

I was thinking the '70 heads, intake and carb and the HEI on the '74 400 block.
Can a Holley 650 be rebuilt to pump enough gas for a 400 engine?
Will either ignition work with a future MSD or just the HEI?
Can I install the '70 intake and carb with the 4x heads to get rid of the emisions?
I think my turbo 400 tranny has a long tail shaft...is this a problem in firebirds other than driveshaft length?

The car is a 70 Esprit, original drivetrain long gone.

Thanks in advance,
Mike

If you have the original quadrajet off the 400 I would use it don't bother with the holly, as for the heads it really depends on what your end goal is.
As far as the tranny goes getting a driveshaft sized up doesn't cost much.
Sorry I can't be much help others should chime in soon.

Your all over the place there,hard to make heads or tails of what your asking us?

Lets start with this,the edelbrock performer & holley carb should fit all those heads no problemo together as a unit.

Now are you talking a fresh engine build here??

Or are you asking how best to "spice up" that running '74 400 of yours???

If the later of those two,we'll need to know exactly what size 5C/6X heads you have.

If the 5C or 6X heads were of the -4 variety,those would be my choice with a slight milling done to them.

-8,well no deal there,next.

Me,I would'nt wanna use the #11's without putting a whole lotta work into them.

I hate pressed stud heads for one thing,wont use them unless converted to SIS.

I also would'nt use a longtail TH400 in second gen bird either.

I convert mine to short tail,but that requires complete disassembly and the proper spare parts to do so.

Points or HEI can work with an MSD as well.

Anyhow,more info is needed for further advice.

:noidea:

Bret P.

those "11's" are low compression 350 heads. i think they make 8.8:1 on a 350. besides needing screw in studs; they have no outer holes for headers; and small valves.
however...i had a 1970 wu(?) 350 w/ those heads and it ran great.
the 6x's can also be used for a nice 455 combo.

I'm planning to run the engine as is for a while with the exception maybe of the 70 intake to get rid of some emissions parts. When the funds permit I would like to rebuild for a little more performance out of the engine, that's when I'd like to put on the 11 heads.

The 5C/6X heads are 8's, I realize the 11's will need SIS, larger valves (196, 166 stock) and tapping for outer exhaust bolts, but thought the extra work might be cheaper than other heads. The 400 came with 11 heads in '70 - albeit the low end 400, advertising 8.6 CR and 80cc combustion chamber (according to wallace racing), and since my car's a '70, I thought they'd work good.
Can I use the '70 intake with the 74 4x heads? Is this when you need to block off the exhaust crossover like I've read about?
What is involved with using the 74 quadrajet on the 70 intake, just blocking off extra vacuum lines?
Will the tranny fit without bashing the tranny tunnel? Is it just not correct for the firebird purists or are there physical issues? Long term plan is an OD auto - prob 700-4r.

Thanks again and sorry for rambling, way to much info on here, hard to decipher what is relavent to me sometimes.

Mike