iree75

I’m a newbe to the forum. What a great wealth of information this site is! I’m looking forward to contributing. (Even if it's on what not to do.)

I’ve owned a 75 L48 4sp coupe for about 5 years now. The car has just about 100k miles on it now. I’ve been kicking around possible engine upgrades and settled on the idea of a 383 crate motor……that is until I ran across a complete built 454 that I purchased for many thousands less than the crate motor would have cost from a person I know and trust. It’s supposed to make better than 500hp on pump gas. (I can only guess at the torque numbers..) (I love torque…)

I’ve found a great post on this from “Fastguy” in the archives, but I’m looking for other experiences of doing a SB to BB swap. The engine has a dual quad setup right now, which will have to go if I want to keep the stock hood. However, I’m considering replacing the hood just because a dual quad setup makes me smile. Any thoughts on that?

I’ll be updating my profile with pics in a few days….

Cheers,
-Frank
:cheers:

Tom73

You will need to upgrade the cooling system, new radiator and shroud. Then upgrade the suspension to handle the added weight in front (and don't forget the rear suspension to balance the changes). Then there are all the accessory brackets. Otherwise it is basicly a bolt in job.

tom...

Ironcross

A good fuel induction system would be a tri power unit to match you heads. { oval or square port } from a 68 or later and you would not need a new hood. :thumbs: :cheers: :cheers:

iree75

Kewl. I like the sound of a tri-pwr setup. (If I can find one cheap enough.) As far as the suspension goes it is going to get rebuit when the motor is out. (All of the bushings are original.) I plan on using an aluminum radiator with electric fans as well.

iree75

Round Rock eh? I just moved down here from Chicago. It's going to be nice not to have to put the car away for the winter! (Unless of course it is being upgraded ;-)

Tom73

Just don't forget to use stronger springs for the added weight. And then be sure to ballance the rear for the front changes.

tom...

ORVette

Does your new engine have oval or rectangle port heads? It will make a difference in your intake selection, at least in regards to what is available to fit under your stock hood with no complications. User "Bob Turner" just completed a BB swap on his '74, and has been a lot of help in figuring out what parts and parts numbers I need to do mine. Figure on $1-2K(USD) in pieces and parts to get it in there and make it work right.

iree75

The heads have rectangular ports. Thanks for the info.

As for the springs, I was just going to use whatever a 74 BB used as a stock replacement. I don't need anything special, as I don't plan on autocrossing it...

iree75

I was hoping to not have to swap the rear spring as the whole rear suspension, diff, spring axles etc.. are fairly new. But it does make sence that if I change to a different spring on the front... Do recommend someone to buy a set from? I always see ads for Performance Suspension in Super Chevy? How are they? I was going to buy the front bushing set from them.
-F

2nspire

With all that torque, you like so much, and I'm not sure for your year, but the drive and half shafts as well as the u joints might have to be beefed up. And then while your at it itis, why don't I just pop in a nice ROD 6 speed tranny, and then there is a 4 or 6 link and on and on and ...... :D

norvalwilhelm

However, I’m considering replacing the hood just because a dual quad setup makes me smile. Any thoughts on that?

This is my 75. About 13 years ago I replace the small block with this bigblock and I like the dual quads.

GWHITE75

Do the BB thing. You will enjoy it. Just need to spend a little more $$ on pulleys and headers. My car was a 75, 4 speed L-48. You will need to evaluate your front end suspension. With 100K, you should probably rebuild it and replace the springs/shocks with aftermarket items or at least OEM specs for a 74 BB car.

The aluminum radiator sounds good and I have one in mine, but do some checking with people located in your part of the country as to the functionality of electric fans as a means of keeping your engine temperatures down in the summer. I run an 18" clutch fan and full shroud which keeps my BB running 195* during the summer months, with the A/C on. Make sure you really seal around the radiator, including between the radiator mount and hood.

As for the hood, your stock hood will probably not work. I run a Weiand Stealth manifold and Holley, with a 3" dropped base air cleaner and it barely fits under my aftermarket hood with a raised cowl. Beings that you will need to replace the hood anyway, you might like the novalty of the 2-4 setup. You might even like it better if you sandwich an 8-71 between the carbs and intake like Norval did.

One note worth mentioning, I purchased my front clip from Ecklers and my hood from a lesser known, but still making the car shows vendor. The difference in quality is very apparent. I paid a little more for the front clip from Ecklers, than I would had I bought it from the same lesser known vendor, but its worth the extra cash in ease of prepration and looks. If I had to do it over, I would have waited and bought my hood from Ecklers as well.

iree75

Very nice. The blower does help getting the carbs into view I see... :yesnod:

iree75

I just replaced the front (stock) and rear (custom fiberglass) bumper covers with ones from Ecklers and am very happy with both as well as thier service. As far as the blower goes, I'll start with just the 454 take it from there.... (My wife doesn't give me any grief for any of this until I mention adding stuff that will stick out of the hood....strange huh?)

74-Roadster

Norval,

Happy New Year!!! That picture just makes me Smile :D