305 to 350
 

Hey i was thinking about dropping a 350 in my truck. The engine comes with everything except a starter and alternator, so there is no major parts that need to be switched over. I was wondering if there is anything you guys know of that will have to be changed in order to go to a 350 from a 305. Will the manifolds bolt right up? and how about the motor mounts... will they need to be changed in any way? thanks alot, NICK

Is the 350 the same era as the 305? I was thinking 86 was about the time GM went to a one piece rear main seal from the 2 piece. The flywheels don't interchange between the two styles. The other problem can be the dipstick. They were on the passenger side until the late 70s or early 80s, the later ones are on the driver side. This can cause a problem if the exhaust manifolds don't match the dip stick location. Everything else will swap over.

86 GM went to 1 piece rear main seals and the dipstick went to the passenger side, early models had dipstick on driver side :D

One other thing I remembered is if the 350 has an aftermarket intake and you have air, make sure the manifold has the required threaded boss for the A/C bracket that attaches to the intake on the driver side.

You might also make sure the manifold has all the required bosses to mount the factory bracket for the accelerator cable. Some of the earlier aftermarket intakes didn't have all the required threaded bosses.

I stand corrected on the dipstick location. I must have gotten condfused, my 84 has a 73 vintage 350. :lol:

Yep alot of people get confused on that issue, your 84 engine would have had the dipstick on the drivers side also, I think. ;)

I think the knock sensors are different.

manifold won't work period unless its a 4 barrel 305. I think GM went to 4 barrel 305 in like 83, but don't get me lying.

I think 80 was the first year for the pass side oil dipstick. 86 was first year for 1 piece rear main, 87 had centerbolt valve covers and little distributor.

I just did this on my 81 and the oil dipstick thing was a problem but then I also realized I needed new exhaust manifolds or headers to fit the different bolt pattern aka the 7th bolt. I solved it all by adding some edlebrock headers. now the exhaust bolts up and I can use the dip stick. Easy swap really. good luck.

my 83 with a 305 had a 4 barrel

my 81 had one too! In fact I used my intake and carb off of the 305 to put on the 350

Yeah i looked today in LMC and 81 was first year for 305 to have a 4 barrel. GM called it a "high output" 305. My 80 has a 305, and its just fine for me :)