305 to 350

[seannz28]

some of you may have reas my post about my 305 rebuild, but after asking around, i have found that 305's are useless....so I am dropping a 350 in it that I have in a different camaro....here are my draw backs
1. the 350 WILL NOT pass DEQ, so I am getting some emisions legal headers, edlebrock tubulars, and gonna weld in some cats, but there is still the emission ports on the intake manifold (I am talking abomut an 82 carbed camaro by the was)... the 350 doesn't have those ports....but the 305 does. I have heard that the two are interchangable...is there any truth to that
2. The 305 is a 4-speed saginaw, a muscle car transmission. the 350 has the 3speed auto. will the belhousing and flywheel from the saginaw bolt to the 350?
3. how can I tell what rear end is in each of them....I want either 3.73, or 4.10....I am not too concernd about highway driving, I live in the suburbs. are they all 10 bolts despite the ring and pinion ratio?

*NOTE* I will have to get back to you with the casting #'s

[Detroit_Bird]

As far as the trans goes, they will both bolt up to either engine just fine, however, the 4 spd requires a flywheel and the auto (TH350 ?) requires a flexplate. Not much difference, but you will want to change them out.

For the rear end, all 82-02 rears are 7.5 in, however the pre 82 rears are different and will not interchange. In order to check your ratio (without a spec sheet) put a mark on the driveshaft and one on a rear tire (paint pen works) put the trans in neutral and rotate the wheel one full revolution (make sure both rears are turning not just one) and count how many times the dshaft goes around, estimating the last turn (0.42 0.73 0.08). How many times the driveshaft rotates is what the rear gear ratio is.

As to the intake emission ports, I'm assuming you mean EGR holes and if the 350's intake doesn't have them then I would assume it was a non-emissions intake and not what you're looking for. An intake from a 350 will bolt on to a 305 and vice versa, by the way.

[Dave M]

Not all 3rd gen came with 7.5 inch 10 bolts. The two cars that you're working with probably did, but I know that some GTA had an autralian-made 9 bolt. It's hard getting gears and parts for those rears, but I don't believe you should have those rears. There should be a small tag bolted to the rear, it will either tell you the ratio or give you a code to figure it out. I also suggest trying www.thirdgen.org. Lots of knowledgeable people over there tat have done this swap before.

[Mirroredshades]

Detroit_Bird is on the money. When checking the rear axle ratio, make sure both wheels are turning in the SAME direction.

Good choice on the switch to 350. Parts are much cheaper and easier to come by.