Thread: big block swap into 3rd gen firebird

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right now my 396 project is near complete and will be running soon. I just bought a 1990 firebird with a lame 305 TBI. the 396 will be going into the firebird. I was just wondering if anyone has experience with kind of swap. I have moroso big block springs up front and subframe connecters in the back. I just finished the 12 bolt with new moser axles and detroit locker and 4.10:1 gears and is now installed. I have a aftermarket turbo 350 with reverse gear pattern and 2.75 first gear with 3000rpm stall converter. i just finishing up the loose ends of the car. the under hood has a mess of fuel injection wires and crap. I was wondering how i should go about the 396 ignition? the motor has aftermarket HEI. Is there a way i can wire the ignition from the car by bypassing the computer or do i have come up with totally new ignition circuit, do i have get MSD box or what? I kinda like to use the factory speedo and the rest of the guages, but i assuming the computer is tie in it all. obivously this is a b***h and i wish the car was originally carbureted. if anyone has this kind of experience with a swap like this, much help would be greatly appreciated!

You won't need the computer or harness. For the ignition, the hei is a self contained unit so all it requires is a hot lead from the ignition switch to the plug in on the distributor. There are two connections on the distriibutor, one for power and one for the tachometer..

thanks very much!

i thinking about putting a 454 and 400 tranny in a 89 camaro and you are the only one that seems to have done this--what i would like to know what did you do to complete the swap was it an easy one-

actually the swap was pretty straight forward and was not that hard at all. everything bolt up without a problem and i had plenty of room in the engine compartment for the motor. since you are using a turbo 400 you have to use shorter drive shaft (400's are longer than 350's and 700R4's) i used a turbo 350 so i had no problems. just make sure put stiffer springs and put some sub frame connecters and might want to do something about that weak 10 bolt. overall the swap was worth it and just the other day i kicked the crap out of a 383SBC camaro, good luck!

what springs do you recommend and sub frame connect where do i get those what ex.manifold did you use---what motor mounts-
thanks for the in put

I highly recommend moroso trick springs for the 82-92 F-body for the big block. those trick springs are just awesome. when you hit the gas the springs kick up and transfer the weight to the rear axle, so better 60 foot times!, i used edelbrock rear shocks and springs. i used the cheaper jegs 82-92 f-body connectors, i recommend you get the weld in style connecters over the bolt in because the weld in provides more rigidity and less flexing. just make sure you have someone who really knows how to weld

i used hooker super competition headers for the 82-92 camaro and they fit nicely. you probably could get the factory BBC manifolds to fit too. i used motor mounts from a BBC chevelle and got them for $35.00 on ebay and they work great.