GeorgeA

I have a 61 with a 283 230 hp 4 speed. Would like to swap for a 350 290 hp crate. Will all components fit? Harmonic balancer, flywheel, etc.The 283 will be re-built and re-installed later when I do a body-off.

Thanks, George

midyearvette

you may encounter some kind'a funky scene with the water pump, front mount and balancer as far as belt line up, an expert will chime in
if you buy one with a one piece rear main, you may need a new flywheel specific to the new mill
everything else should fit sans maybe the valve covers ..good luck...

jimh_1962

No, You will probably will have to replace the harmonic balancer 6 in versus 8in, generator, exhaust manifolds, starter and new carb which is probably too small for the 350. You will want to upgrade your intake.

What is wrong with the 283? I am sure you could beef it up to run close to 290 HP.

Stewart Allison

350 should bolt up spot on ! Use the 283 water pump I had trouble with the mount bracket loosening and causing the water pump to leak. I found that the block on the 350 was not letting the bracket sit flush so I die grinded the block until it sat flush. everything else just bolted up. It does good skids with the 350 more torque yippy ! But not standard Stewy

midyearvette

i think there is a spacer on the c1's that goes between the crank and balancer??

GeorgeA

Would a 63 340hp aluminum intake manifold work on the 350/290hp ?

George

Stewart Allison

I think it will. I spaced my balancer out so the belts would line up straight if I remember. Nearly everything in Small block Chev is interchangeable. The 63 340 hp manifold should do the trick I think ? Stewy

wmf62

you don't say what year/version 350... but, i have a 1970 350 LT-1 CE engine in my 62 and it fits just fine, with no modifications.
Bill

GeorgeA

The 350/290hp is intended for use in 1985 and prior years

George

GeorgeA

Bill, What intake manifold did you use?

George

wmf62

i mounted the C1 Rochester FI, plenty of room for that...; if that fits, then just about any intake/carb should work




Bill

5869vette

If you are running a 4 speed, you might need
to put in a pilot bushing in the crank shaft.
290 horse crate motor is a great motor.
Nesmith Chevy has the base motor for $1900.
Plus free shipping. It would be hard to rebuild
a 350 for that amount.

GeorgeA

I was worried about hood clearance, but I guess that won't be a factor. I can get a super deal on the 290 hp, customer ordered and changed mind, no return policy on crate engines.
They just want to get rid of it. I win.

NOM61

Yes. To compensate for the thickness of the motor mount plate.

One of the primary differences you will have to deal with is the lack of a road draft tube on the 350.
You will either need to use valve covers with a pcv (assuming you are using an intake with an oil fill tube/vented cap) or modify the intake to accept a pcv if you want to use the original covers.


DT

wmf62

yes there is, BUT i ran my LT-1 engine for over 30 years without the spacer and the slight belt misalignment never casused a problem. (i never knew at the time that one was even used... )

no big deal to pull the balancer and install a spacer though...
Bill

584me

Put a 350 crate in my 58 Vette and I had hood clearance issues with the air cleaner-- air conditioner compressor. I put on a serpintine belt driven system. The guys at Pace Automotive said I would have a problem with it and they were right.

NOM61

Fully dressed crate motors are not the best way to go. A tall dual plane manifold with a big 3 inch filter sitting on top of the carb will never clear and as you found out, the head mounted accessories and potentially a long water pump can be a problem.
Much better to start with either a short block or basic long block, then add the appropriate intake manifold, carb, air cleaner, and exhaust manifold mounted accessories. Everything from the 283 will work - the blocks are dimensionally the same.
A larger harmonic balancer and a modified pcv system are the only real changes required from the 283 if you are using a 2 piece rear main gen 1 350.

DT

Stewart Allison

Yes I also used a PCV in the valve covers. Works real good. I pulled the little heat pipe out of the exhaust manifold. I believe if you run a holley on a low edelbrock manifold it clears with the stock air cleaner. I have an edelbrock carb and I had major issues in clearance. The holley must be a shorter carby ! Stewy

GeorgeA

They do suggest 2 harmonic balancers for use on this specific engine 6.75" or 8.00". Should I use the larger one or does it matter? George

wmf62

no, it really won't matter for your application. when i did my IFS conversion my original 8" balancer hit the new crossmember so i had to change to a smaller diameter one.

i have noticed no issues with the smaller balancer.
Bill