Bubbajones_ya

I have a build thread started in the TBI section, but figured I'd post a new thread here with this specific question since it's not TBI specific.


I have a mild cammed 305 TBI 91 camaro that I'm going to be putting a 350 Vortec Block/heads in. I ordered the proper intake/adapters and gaskets, and will be reusing my serpentine setup, oil pan/one piece gasket, roller cam and valve springs, timing chain, water pump (all these were replaced with new parts about one year ago when I did the work to my 305, so they are still almost new.)

My problem is the 350 vortec block I picked up does not have the holes drilled for the old style timing covers. Also, there is no coolant bypass holes driller for where the water pump bolts up.



I would like to reuse everything I can from my 305 including my water pump/timing chain set and potentially harmonic damper (or buy a new old style damper) so that I can have a pretty much bolt on exchange. I've never had to drill/tap holes on something like this before, and only have hand drills at my disposal.

My questions are:

Can/should I drill these holes with a hand drill?

Do I even need to drill the extra holes for the timing cover, or can I get by without doing it?

Do I need to drill the hole for the coolant bypass, or can I get by with tapping the water pump into the intake? The water pump has a threaded plug on the top, and the intake I purchased says it has a place to thread a water bypass into it. I'm not sure which way would be better.


Thanks for any advice and help!

Biledriver

I'm doing this for my c10 now. I'm getting a new plastic timing cover so I don't have to worry about leaks. I'll have to make my own timing pointer when I degree the cam but I'm cool with that. That will also mean I need to use a replacement single chan to fit under it, but I'm running a standard oil pump it should go a long time no problem.

MoJoe

iTrader: (5)

Bypass - this is to circulate water if the thermostat is closed, and no other external items, like the heater core, allow flow.
1) If you use the factory heater routing, there is always water flowing from the engine (to the heater core, oil cooler, and) then to the radiator.
2) drill one or two small (1/16-1/8") holes in the edge of the thermostat to allow air to always escape, and provide some minimal "bypass" flow.


Footnote 1a) When the heater controls are off, the coolant bypasses the heater core, and goes straight to the radiator.
Footnote 1b) If you have the factory oil cooler, the coolant always flows through that prior to the radiator.

dereklicon

Oh no.... Just get a plastic timing cover for the vortec. Its way easier than drilling or tapping anything. Also, I remember when we did the swap in my buddies 305 TPI camaro we didnt have any problems with the water pump that I can recall. It has been a year and a half since we did the swap. We may have had to buy a new pump, it was only like 30$ brand new or something.

Bubbajones_ya

Thanks for the responses! I do have the factory heater routing so I don't believe I'll have to worry about the water circulation then when I swap to the vortec setup with the new intake.

As for the timing cover situation. I ordered a new cheap chrome timing cover with the gaskets included but for the old style block (since it was way cheaper.) Do you think I can get away without with just bolting that on without the two extra holes, or should I return it when it gets here and order a plastic cover?

Biledriver

I like the plastic, I'll be using it. But I don't think a double chain will fit under it. You'll have to use a stock vortec chain and install the crank sensor reluctor so everything lines up. Chrome rusts fast and looks like garbage quick anyway ( unless you leak a little oil).

Bubbajones_ya

I'll have to see if the cover was chrome or just chrome colored. It was the cheapest one I could find on Jegs at the time.

I was going to reuse the chain and sprocket set I put on my 305 about a year ago since it has very little miles on it and saves me about 50 bucks. I can't remember if I bought a double roller or not though, and wasn't sure if the crank sprocket would fit without an older style cover as well. On top of that, I was going to use an older style harmonic damper too which I don't think works properly unless the sprockets/timing cover match it.

I suppose I'll be finding out soon enough though. I'm hoping I can get away without drilling anything and using the cover I ordered!

redneckjoe

may want to do some research on the balancers? some have 12 o'clock marks, and some have 2 o'clock marks. a few different sizes also, from around 6 3/4" up to 8". i think i'd pick up a vortec 350 harmonic damper if they're cheap enough.

i'd also run the plastic cover.

you might be surprised how much your 1 year old chain in the other block has stretched already? especially if it was a cheap one, even a double.