[rcread]

I have a 1978 Firebird Esprit (Skybird). This car has a 130 horsepower Chevy 305 engine. I obtained a 40,000-mile Pontiac 350 from a 1974 GTO (200 horsepower) and would like to swap out the 305 for the Pontiac engine. The obvious benefit is that it makes more power, but it will also make it easier to drop in my 455 when it is finished. To drop it in place, do I just need the proper engine frame mount brackets? I know there are a bunch of other differences (e.g. bellhousing adapter and all the accessory mounts), but I want to address engine placement in the car first.

[thepontiacman]

Frame engine mounts(clam shells), engine side motor mount bkts(F-body)., fuel lines need to route to driver side of frame. Staarter is on driver side for Pontiac so wires will route to driver side.

Pontiac Acc.Brackets and pulleys will work from the 350 pontiac to the 455 when you change to 455, it will be easy.





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[ponyakr]

Yeah, I did this on a 1980 Bird.

Just have to get the clam shell frame mounts bolted down, in the correct holes.

Didn't have any trouble with the pass side.

But, I couldn't figure out any way to hold the backup nuts on 2 of the driver side bolts. Probably just me. Was my 1st time doing it. Others can probably tell an easy way to do it.

The best way that was suggested to me was to just make a hole in the front of the crossmember, big enuff to get a box end wrench thru. There were holes in pass side, but not the driver side. If I'd had a torch, I'd have made the hole & been done with the job quick. That's what I'd recommend to anyone doing this job. But, for those who don't want one extra hole in your crossmember, there are other methods.

I used oversize 7/16 bolts, & tapped some threads in the thin frame crossmember.

The 305 mounts were welded in. I suppose that if you use my method, some minor welding might not be a bad idea, on the DS mount, AFTER you are sure you have 'em in the correct holes.

I wasn't worried about the mount, because I knew I'd be chaining the DS of the engine down.

I had a little trouble getting the PS block mount to frame mount bolt started, but eventually got it in.

https://forums.maxperformanceinc.com...8&postcount=45

[Sirrotica]

FWIW, drilling a couple holes in the crossmember big enough to get a swivel socket on an extension is how I do it. One hole on each side you can get 3-4 nuts on each mount. I use a stepped unibit drill to get a large enough hole to pass the socket through.

The factory puts the nuts/bolts on before they attach the lower control arms, but it's usually not efficient time wise to remove the lower control arms on an older car.

[Formulabruce]

The factory trans may NOT be a BOP bellhousing type.
Better check so you dont need to source a trans as well.