I have 1986 Chevy Silverado. When taking the 305 out and replacing with a 1991 350 does the transmission flywheel and torque converter have to be changed? Yes it's all chevy Thanks boB
I recently replaced a 305 with a 350 in an 84 Monte Carlo and it had the 350 turbo transmission in it from the factory so everything worked great. GO 24!!!!
If you are talking about using the flywheel and torque converter which is in the 1986 5.0L 305 with a THM400 or THM700R4 tranny it will be an exact match when bolted to the 1991 5.7L 350 you are dropping in your 86. But if you are talking about using the flywheel and torque converter which is bolted to the 1991 5.7L 350 then that flywheel and torque converter will only be a match to your 1986 THM400 or THM700R4 tranny if the 1991 has the THM700R4 tranny. If the 1991 has the 4L80E tranny then that flywheel and torque converter will not match your 1986 THM400 or THM700R4 tranny. Use the flywheel and torque converter which is on your 1986 THM400 or THM700R4 tranny and you will have no problems bolting that 1991 5.7L 350 to your transmission. All of the engine accessories from your 1986 5.0L 305 will also be an exact match when bolted to the 1991 5.7L 350, including the starter, alternator, water pump, and even the 1986 5.0L 305 intake manifold, carburetor, distributor, and engine control computer. The only thing I can think of that you cannot transfer from your 1986 5.0L to the 1991 5.7L 350 is the harmonic balancer and you will need a harmonic balancer for a 1986 5.7L 350 to put on that 1991 engine so that your 1986 305 crankshaft pulley will bolt to the 91 engine. Other than that I think it will be an easy job with few problems.
The engine and transmission will bolt up, and the flywheel on your '91 350 should fit the torque converter on the '86 transmission. If not, you could use the flywheel from the 305 on your 350 engine. For sure there will be a snag or two, but nothing that isn't solvable.
