Ok so,

I recently got a 260z bone stock, also my father owns a salvage yard and a 78 280z came in pretty much complete so its like a parts car. After that i traded some interior parts off the parts car for a 260z motor that has a header and a set of wheels. i picked up the motor and it turned out to be a 240z motor with a e31 head on it.

i want to build up my 260z motor a little.

i plan on putting weber dgv carbs on it along with the header.

My brother works at a motor building shop so i was going to have the e31 head planed, ported a little, polished, and put bigger valves in it.

is this going to make a big difference in the performance and will my compression be to high to run pump gas?

also what difference will the carbs and header make?

Why Weber DGVs, just out of curiosity? I'd rock SUs all day long over DGVs. The only Weber that belongs on an L2X is a DCOE, IMO.

I'd read this whole page before you attempt anything:

http://datsunzgarage.com/engine/

I had dgv's on my motor. The SU's were a big improvement.

Alright thanks for the link, i was under the assumption that the dgv's were easier to adjust and had better flow. I think i have su carbs, but not sure is there a way to tell? i attached a picture.

Just curious. Where did you hear/read that DGVs were easier?

As for determining whether or not you have SU carburetors, there is this way. You could also download factory service manuals from the early model years. (I highly recommend downloading FSMs from different years, especially if you plan on putting parts together from different model years.)

The bottom line is that those are early SU carburetors in the pictures.

He might be wondering if he has the "good" SU carbs, i.e. not the flattops—which he doesn't, thankfully.

SUs are very easy to tune and flow more than adequately for excellent street performance. Watch this and you'll learn everything you need to know:

http://ztherapy.com/products/videos/just_SU.htm

The real downside to DGVs, IMO, is the manifold design, and the way the mixture has to make an abrupt 90° turn right after the venturi. It's bad for flow, makes it harder for the air to keep the fuel in suspension, and even creates a fire hazard if the fuel puddles at the bottom of the manifold.

I'm a liitle confused of what you have from what car, but I would look closely at that L24. Do you know anything about any of these engines. Does the L24 need to be rebuilt and why are you stuck on making the L26 work.

If it were me, I would want to make the E-31 head work on one of the blocks, it doesn't really matter which one, but do your research. The E-31's had issues and need some close scrutiny, but if I was going to pick a head to invest in a rebuild, it would be the one, and I would probably stick with the L24.

Done any compression checks?

There is a lot of info on here and Hybridz as far as mix and matching of parts

Just curious. Where did you hear/read that DGVs were easier?

As for determining whether or not you have SU carburetors, there is this way. You could also download factory service manuals from the early model years. (I highly recommend downloading FSMs from different years, especially if you plan on putting parts together from different model years.)

The bottom line is that those are early SU carburetors in the pictures.

i met some guy at a car show who said he went from his stock carbs to dgv's and he told me it made a big improvement. i dont know what style carbs he had stock.

I'm a liitle confused of what you have from what car, but I would look closely at that L24. Do you know anything about any of these engines. Does the L24 need to be rebuilt and why are you stuck on making the L26 work.

If it were me, I would want to make the E-31 head work on one of the blocks, it doesn't really matter which one, but do your research. The E-31's had issues and need some close scrutiny, but if I was going to pick a head to invest in a rebuild, it would be the one, and I would probably stick with the L24.

Done any compression checks?

There is a lot of info on here and Hybridz as far as mix and matching of parts

What i have:

i have a complete 280z motor

240z motor w/ the e31 head

and a 260z motor with a e88 head

The L24 needs a rebuild

And i want to build the L26 motor because its already runs and is in my car. i just want to make a more power for the street and get a better sound.

i haven't done any compression check also a lot of my vacuum lines are dry rotted and need to be changed.

He might be wondering if he has the "good" SU carbs, i.e. not the flattops—which he doesn't, thankfully.

SUs are very easy to tune and flow more than adequately for excellent street performance. Watch this and you'll learn everything you need to know:

http://ztherapy.com/products/videos/just_SU.htm

The real downside to DGVs, IMO, is the manifold design, and the way the mixture has to make an abrupt 90° turn right after the venturi. It's bad for flow, makes it harder for the air to keep the fuel in suspension, and even creates a fire hazard if the fuel puddles at the bottom of the manifold.

alright just wasn't 100% sure what style i have, and thanks ill check out the videos

Drop in the 280 and bolt on the SUs.