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Differences in 1986-1987 and up 350's?

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Old 02-26-2006 | 03:19 PM
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Default Differences in 1986-1987 and up 350's?

87' was the 1 piece rear main seal, and roller cam? Is that all? Im trying to figure out if I can use my balancer and flywheel from an 87 305 on an early 350 with 2 piece rear main. Any why does edelbrock offer 2 different performer intake if the only differences were roller cam and rear main seals?

I wish this boat had a big or small block ford in it. Same **** since 1969
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Old 02-26-2006 | 03:32 PM
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Default Re: Differences in 1986-1987 and up 350's?

different head went to the center bolt head...differant mating surface at intake
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Old 02-26-2006 | 06:47 PM
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Default Re: Differences in 1986-1987 and up 350's?

Woody,
If your 305 is a one piece rear main seal, you cannot use the flywheel on a 2 pc crankshaft. First of all, the bolt pattern is different, but more importantly, the one pc seal flywheels have a weight built into them and will throw a 2 pc seal crankshaft out of balance.
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Old 02-26-2006 | 06:59 PM
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Default Re: Differences in 1986-1987 and up 350's?

You cant interchange the balancers either.
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Old 02-26-2006 | 07:09 PM
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Default Re: Differences in 1986-1987 and up 350's?

Madness I tell ya, chevy madness, thanks guys
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Old 02-26-2006 | 08:43 PM
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Default Re: Differences in 1986-1987 and up 350's?

Originally Posted by BillK
Woody,
If your 305 is a one piece rear main seal, you cannot use the flywheel on a 2 pc crankshaft. First of all, the bolt pattern is different, but more importantly, the one pc seal flywheels have a weight built into them and will throw a 2 pc seal crankshaft out of balance.
Ya according to block casting it is indeed a 1 pc seal, that really jams me up on the current parts I have gathered thus far for the repower
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Old 02-26-2006 | 10:18 PM
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Default Re: Differences in 1986-1987 and up 350's?

Woody,
I just remembered... I have a flywheel that came from a 1990 260 h.p. small block Merc motor that had a 1 piece seal. I can cut you a deal on it. If interested, I can send you a picture.

Vinny
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Old 02-26-2006 | 10:25 PM
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Default Re: Differences in 1986-1987 and up 350's?

Originally Posted by checkmate454mag
Woody,
I just remembered... I have a flywheel that came from a 1990 260 h.p. small block Merc motor that had a 1 piece seal. I can cut you a deal on it. If interested, I can send you a picture.

Vinny
pm sent
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Old 02-27-2006 | 05:46 AM
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Default Re: Differences in 1986-1987 and up 350's?

First, if your looking to upgrade a Merc built engine, they didn't use roller cams till sometime in 88. Even then depending on S/N it could still have a flat tappet cam. Roller cams were installed mid year in 88.
The differences in intakes is again depening on what heads were installed. The older heads had the center four bolts drilled on the same angle as the other bolts. Newer heads had the center bolts straight up, not angled. Vortec heads have no center bolts.

And, as far as I know the balancer and flywheel from a 305 is not the same as a 350. I believe the balancing is different.
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Old 02-27-2006 | 06:55 AM
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Default Re: Differences in 1986-1987 and up 350's?

Originally Posted by Iggy
First, if your looking to upgrade a Merc built engine, they didn't use roller cams till sometime in 88. Even then depending on S/N it could still have a flat tappet cam. Roller cams were installed mid year in 88.
The differences in intakes is again depening on what heads were installed. The older heads had the center four bolts drilled on the same angle as the other bolts. Newer heads had the center bolts straight up, not angled. Vortec heads have no center bolts.

And, as far as I know the balancer and flywheel from a 305 is not the same as a 350. I believe the balancing is different.
I thought it was '87 when the roller cam version came out, did it take awhile for Merc to get these newer engines? I was hoping mine was a roller, is an '87, won't know for sure 'till I pull intake I guess?
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