I have a 68 convertible that I am restoring. It is a 400 4 speed car and it is matching numbers. The engine block is the WZ Code and it has the 16 Heads. I just had the engine rebuilt with the block bored 30 over. I put the Ram Air IV Cam in it, everything else is stock. I have the original intake and a Rochester carb with the casting number 29244 KA 1539 which does not appear to be original according to my research. I have rebuilt the Muncie M22 4 Speed and have rebuilt the rear end with 3;36 gears that it originally had. I am getting ready to put it back together. This is a car I am going to keep and I am keeping it close to stock in appearance , being a matching numbers car. However, I am considering putting a different intake and carb and HEI for better performance. Also considering the reproduction Ram Air Headers.
Any suggestions for intake, carb, HEI ? Edelbrock combo? I have read that there may be clearance issues with the RPM series. The original intake appears to be in good shape and is an option with a rebuilt Rochester. Am I thinking right that I would be better off with a new aluminum intake and modern carb? Also I have original radiator but would appreciate recommendations for a good aftermarket one. As far as suspension, I went back with stock components. I kinda wish I would have got the springs to lower it a couple of inches but I didn't. It has been recommended to me to get the weld in sub frame connectors, any suggestions there? How about exhaust system recommendations?
Last but not least, I have a set of 14" Rally ii wheels but would like to get some new wheels and tires for appearance and stance. Any size recommendations and rim suggestions? Money is a factor but I have went this far so I'm more concerned with doing it right rather than saving a buck . Original color is Meridian Turquoise, Deluxe Black Interior, White convertible top according to PHS DOCS which seems unusual. I have been working on it for 2 years and I'm ready to get this bad boy on the road! Thanks before hand for any advice.

David

If you have gone stock that far, I'd not even consider switching to Edelbrock or anything else. Get a correct quadrajet and intake. You should find dozens of threads on this site from members going different directions, only to realize their mistake and go back to stock. Pontiac engineers did know what they were doing back then.

The "regular" Edelbrock Performer intake manifold is pretty much an exact copy of the factory Pontiac manifold except lighter. The RPM places the carb about 1.5 inches higher than stock. Might cause hood clearance issues with a stock air cleaner. Definitely causes issues if you decided to add an aftermarket Ram Air setup. Keep the Qjet.

I am really likeing my aluminum Rodney Red radiator. As my build was progressing, I constantly saw overheading issues and was determined to avoid them. If you do a search here you will see that making sure there is minimal clearance between the water pump impeller and rear plates makes a huge impact.

Subframe connectors are typically a good idea for a 'vert, especially with more HP than stock.

You definitely will want to stay away from 14 inch wheels if bone stock is not your thing because one nobody except repro tire places deal with that size anymore. That's also starting to happen at the 15 inch size (Firestone Indy's are gone for instance). Year One now offers larger Rally II reproductions and Vintage Wheel offers even larger "rally II" look billet alumium wheels. Tire size becomes really critical at the larger sizes and I would recommend doing a search here to see which size combos work best. My thinking was to always go with a final diameter that is really close to the factory E size that came on my car.

The stock Pontiac cast iron intake flows VERY well. For the motor you are building even with the RAIV cam (which I think is too much cam for that combo) the factory cast intake will be fine. I wouldn't even consider an aluminum intake unless you are planning on some serious track time.

Not only are there fitment issues but you will have to do some minor mods to get the throttle cable to work.

As for the carb, I'd send a correct Q-jet off to Cliff Ruggles to have him work it over for you or at the least buy one of his rebuild kits and do it yourself.

Good advise.

Have the intake ports been enlarged? If not I would use a 68-70 stock intake and clean up casting flash.
Separate the water x-over to line up ports better. Then check how well they line up. May need some extra clean up for good port match.
The RPM intake has larger RAIV port size. And need a drop base air cleaner if you use one.
76-79 Q-jets are my fav's do to the APT circuit.
HEI wont get you more power vs points. But the hotter spark is better for tuff clean idle(fuel drop'n out of suspension) on some builds.

BTY, lets us know how you like the RAIV cam with 3.36's.
I have RAIV with 3.42's and its slow off the line. Even w/a 3500 stall convtr. At least compared to the last one with 3.73s.

GMW468 pretty much covered it. Keep the stock intake and have Cliff do your Q-jet. There are plenty of kits to keep the stock distributor but get rid of the old points. I'd go that route since yours is numbers matching rather than a true HEI.

I'd also agree the RAIV cam with 3.36s will be disappointing especially with the rest of the engine being mainly stock. If the engine isn't fired yet (or even if it is) sell that cam and find something else. Something with a 112 LSA and 214-216 intake/ 224-228 exhaust (@ 0.50) and lots of lift.
Crane Cams 283941 - Crane Hydraulic Flat Tappet Camshafts
Summit Racing SUM-2801 - Summit Racing® Camshafts
This one might be at the top of as high as you'd want to go.: Crower 60242 with 221int/229ex

Or even better would be a complete hydraulic roller setup. This can really wake an engine up while appearing stock.

If you really have your heart set on trying that RAIV camshaft, I'd recommend to at least set it up 4 degrees adavanced.