Installed a raised crossmember...now what

[2wd73blazer]

I have installed a raised crossmember on my 72. I have a BBC to install when I get to that stage. I have a couple of questions. What headers do you run with this setup? I have long tube Hooker headers I bought before I decided to lay frame but I think they will stick out below the frame. My second question is about a/c. I have a a/c cab but my tires are 28.5 inches tall. I believe I read on here that if your tires were over 28 then they would hit the a/c housing. Do I need to run vintage air or some other aftermarket a/c unit? If I need to run aftermarket a/c then do you have to run the a/c compressor that comes with it? I have a gmpp bbc serpentine system I was planing on using.

[royo]

I dont know about sd stuff but on a dropmember a chevelle shorty header works for me . I think there is a thread on here where someone was working on the ac thing had pics too
look here mabe this will help

http://67-72chevytrucks.com/vboard/s....php?p=3564383

[SCOTI]

I recommend picking up the phone & contacting the manufacturer of your 'raised crossmember' for optimim results w/fitting various parts.

[2wd73blazer]

I did pick up the phone and contact the manufacturer. They had never installed a bbc with the raised crossmember. I imagine running a bbc is not as common as running a sbc but I may be wrong. I was hoping to get input from others who are running a bbc. That is the reason I have posted here.

[lolife99]

The original Dropmember requires a different set of engine mounts for a BBC. I'm not sure if the engine mount "tabs" on the crossmember itself,... are even in the same location as the SBC version. Nate Porter now makes a new Dropmember V3.2 tubular model that is completely different than the two versions I own. I was thinking that the BBC has to be located higher than the SBC to clear the harmonic balancer,... but I may be wrong.

I don't know anything about the Raised Crossmember.
I think SD is the only source for your answer., or try to install your BBC on the SBC mounts and see what hits what.

[2wd73blazer]

Thanks for the reply lolife. I may end up running a sbc just to make my life simpler. I hate to do it because I have a 468 sitting on the engine stand waiting for it. There is a local machine shop that could probably fab me new motor mounts if the ones I have dont work. Does your tire or a arm hit the a/c box when you are aired out?

[PBFAB.COM]

Pretty sure the "Raised Crossmember" is close enough to the Original Dropmember, that I might be able to help you out.

The difference in mounts for the BBC vs. the SBC is the height. The BBC needs a bit more room up front to clear the rack and pinion. The easiest solution will be to make some new tabs for the crossmember that raises the motor up the correct amount. As mentioned by Lolife, our new V3.2 has a modular motor mount system that allows a SBC, BBC, GENIII, and I6 to be easily interchanged.

The BBC is a much tighter fit, and will take a little more effort to get everything set-up, but since you have one on hand... I say run it.

[2wd73blazer]

Thank you for the info Nate. If I could start it all again I would have a porterbuilt suspension. I have nothing against SD. They have been great to work with. I already had their a arms and wanted to keep the brand the same but you will get my business on the next one. Do you have any input on the a/c ? What do most people run when they lay frame?

[PBFAB.COM]

Originally Posted by 2wd73blazer

Thank you for the info Nate. If I could start it all again I would have a porterbuilt suspension. I have nothing against SD. They have been great to work with. I already had their a arms and wanted to keep the brand the same but you will get my business on the next one. Do you have any input on the a/c ? What do most people run when they lay frame?

The A/C is going to greatly depend on your tire diameter. If you want a large diameter tire up front, you will most likely need to remove the factory a/c box or heavily modify it. The "norm" is to remove the factory stuff, and replace it with an underdash system.

Nate

[Wild83C10]

I would suggest that since you have the crossmember in and the engine sitting on a stand drop it in and see where you are at. Then you can determine where you need to go. Just take some measurements. At least you have a starting point. Who knows you might get lucky.

[SCOTI]

I would start with 3/4 length headers for a Chevelle & see how the fit.

[5windowpickup]

I used hedman hedders part # 68610 headers with my drop member. They should work with your crossmember unless something is drasticly different.
Another thing to think about is the air cleaner. A standard 14" wouldn't clear my rear hood brace so I ran a 14" triangle and the straight back cleared the brace. The other option would be an oval turned sideways. The distributor gets tight too so keep that in mind. I think the big block is worth the extra work, I would stick with it.

As for the a/c box my tire clears the box with a 28" tall tire but the upper control arm hits without a drop spindle. Your results will all depend on your wheel offset and etc.

[2wd73blazer]

I am running a Belltech drop spindle. I think it is 3". My tires are 28.5 inches tall. I guess I will have to put the cab back on and see if the tire or a arm hits.