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Straight 6 to bbc help!

1316 Views 2 Replies 2 Participants Last post by  younggun466
Hi all im new to this site i just picked up a 69 nova a few weeks back and i have a question on swapping the straight 6 out for a 402 bbc.

The problem is i cant find much info on going from the straight 6 right into a bbc i can find tons of info on sbc to bbc or straight 6 to sbc but not much at all on what i want to do. i was just wondering what kind of frame mounts and motor mounts i would need for this swap?

The 402 is out of a 72 chevy c20 pickup i own and the nova i believe is just a 250 straight 6 with an automatic.

Also would there be any problem with putting the turbo400 into the nova along with the 402? I thought about switching to an overdrive transmission instead but since the turbo400 is rebuilt and runs great i think ill keep it. Any help is much appreciated! thanks again!
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BBC help

OK, here's some of what you need to do on this swap:

1. Get a car oil pan. The truck pan or Corvette pan won't work. Also plan on puttin in a new pump & pick up at the same time. Minimum is changing out the pick up tube.

2. You need frame stands and engine mounts. Most any vendor can source these for you.

3. The Nova most likely has a Power Glide in it. THe Big Block is going to eat it at some point. Think about going to a TH350 Or TH400. THe 400 will need a different rear mount and the cross member needs to slide back due to a different trans length.

4. You will need to change out the front springs. MOOG makes a good replacement set. I have a set of F41's from a Chevelle I'm not using if you want). Remember once you go into the suspension, you should replace everything with Nova SS396 parts.

5. Radiator - stock replacement for a SS396 or ???? Remember that little radiator is for a little engine. Will work to get the car going, but not much else.

6. Rearend - This will be a 7.5 inch or simular. The BBC will eat this wimpy thing. But the explosion will be neat! Look for a Z/28 or Trans Am in the boneyard. Has the better 8.5 and bolts in.

7. Drive shaft - Get a good one made. They need to know several things about the car & measurements.

8. Rear Springs - SS396 & COPO 427 cars had the F41 suspension. This ment multi-leaf springs in the rear to handle the torque wrap on sudden acceleration. A 6 cyl equiped car has a single leaf set-up for the blistering acceleration that only an I-6 provides! It will break.

9. Fuel line - stock is 5/16", you will need to upgrade to 3/8". It will run with a smaller line, but will fuel starve and effect performance.

10. Exhaust - Kinda self explanitory. Either headers or SS396 manifolds from a Nova or Chevelle or Camaro. Front stub on a Nova is 1st Gen Camaro. Get a decent 2 1/2 " exhaust for it as well.

Front sway bar - upgrade to 1 1/4" bar or 1 3/8"

Rear Sway bar - good idea to add this as well

Another thing to stongly consider is sub frame connectors and a 6 point roll bar to stiffen the car up. Just be sure to check the door gaps before you weld thing up solid!

This is just off the top of my head and others are sure to chime in. I didn't cover brakes at all. Lots of good kits out there. If you stay with the stock units, this car will not stop well due to added weight over the front end. Now having said all of this, you need to start a thread on this site showing progress with pic's.

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Thanks for the help

so basically im just gonna buy the suspension parts for a ss396 and replace it all i did find a hotchkis kit in my classic industries catalog that looked like it had most the stuff i would need.

For the brakes ive settled on a baer brakes kit that im gonna buy. after reading alot of reviews and stuff on ssbc and willwood and others the baer system sounds like the best i know you can get cheaper kits but id rather not risk my life or someone elses by trying to save a few bucks.

i just found some frame mounts for a 69 396 from classic industries now i need to find the motor mounts and im set for that. then ill need new wiring kit cause mine is torn apart right now and i should be good to go for now.

Thanks again for the help! really appreciate it :)
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