older style heads fitted on 96LT1 block

[prairiehotrodder]

i have a 94 roadmaster sitting in my junkyard with the P code LT1. I thought the heads were the best part of that motor ? I was gonna try to swap them onto an older 350. Not sure if its worth the effort anymore if they need rebuilt.

[rfoll]

"Going from iron to aluminum heads is like having one less passenger "...If your passenger is a child. I seem to remember the difference of 40 lb.

[gmrocket]

"Going from iron to aluminum heads is like having one less passenger "...If your passenger is a child. I seem to remember the difference of 40 lb.

40 lbs is a big deal in a boat. We are also going aluminum intake and maybe al water pump.

[rfoll]

I've been doing this boat stuff for about 55 years. I know about weight in a boat. If 40 lb. matters that much, your boat is too small for the intended purpose. If you want to do this for the engineering exercise and the fun of doing it, I do understand.

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[gmrocket]

I've been doing this boat stuff for about 55 years. I know about weight in a boat. If 40 lb. matters that much, your boat is too small for the intended purpose. If you want to do this for the engineering exercise and the fun of doing it, I do understand. ski.jpgif1502320678367.jpg

Ya got me by ten years on the expert scale.

But I'll still take a 40 pound reduction any day..

Call me crazy but everything I do to my own personal boat, 20ft 468" jet drive , I take weight into account.

The boat this topic is about is a 23' I/O runabout heavy deep V design. It's underpowered 350 is tired. It's slow to get up on plane, tops out at about 55 fully loaded.

The block mods for the heads are done. Took about an hour once we figured out what we needed to do.. tapped the 4 large coolant holes for 3/4" NPT black iron plugs.. epoxied in place and flush with deck... grind slots for oil drain back

Plugs were $7 for 4, epoxy $10 thats the cost to mod it for gen 1 heads,, infact, the holes were good enough to be tapped as is. Pretty simple

I'll post some pics

[cardo0]

Hmmm, modifying the block for the head. I didn't expect that. I had the mindset to modify the heads for the block. Pretty creative and hope it works. Please let us know if it can work. There are a lot of us LT1 frustrated by the lack of good manifolding for the Gen II LT1.

Myself I've looked at splicing Gen I and Gen II timing covers to use the optispark distributor on a Gen I block. Yeah that sounds about as crazy as it gets but it allows a owner to keep stock computer (which is the easier route for some of us but of course not all of us).

Let's see some pics.

[rfoll]

" lack of good manifolding for the Gen II LT1". That makes a good validation for the path you are on.

[FC-Pilot]

I'll post some pics

I look forward to seeing some out of the box ideas and fixes. These engines are a dime a dozen around here. It would be nice to figure out a way to make use of them for people on the cheap.

Paul

[gmrocket]

gen 1 style heads oil drain backs line up with this huge hole...which we tapped. epoxied in place 3/4" black iron plug just below the deck. then drilled the small water hole and slotted the area for oil return where it lines up with gen 1 style heads

[cardo0]

Since its now a Gen I block a known practice is to plug and drill all those larger water jacket holes along the high/inside of the decks. I guess the Gen I blocks need some additional back pressure. So plugging and drilling the larger holes down/along that line would only help cooling.

Gen II blocks seemed to be much better casting as you won't/don't see any core shift looking at the lifter bores. But how are you going to install a water pump? I assume you want to use a Gen I water pump?

Thx for the pics.

[gmrocket]

Since its now a Gen I block a known practice is to plug and drill all those larger water jacket holes along the high/inside of the decks. I guess the Gen I blocks need some additional back pressure. So plugging and drilling the larger holes down/along that line would only help cooling.

Gen II blocks seemed to be much better casting as you won't/don't see any core shift looking at the lifter bores. But how are you going to install a water pump? I assume you want to use a Gen I water pump?

Thx for the pics.

Ya we're going to be using a gen 1 belt drive pump. So far it looks pretty easy.

As you might know the front of these where the pump passes water is split into two separate passages...bottom hole connects to lower water jacket and the top feeds up into the heads,, which is the passages we blocked on either side

So what we think will work is removing the casting portion that separates the two passages, make a plate to cover the whole area, then mount a stock pump on that plate

The top two water pump bolts will go right through the block off plate and into the block to keep pump at stock height

Lower bolt holes will attach into the block off plate..

That's the plan Anyone know of a cost effective aluminum gen 1 pump ? Only found one made by GMB North America #130-1250HP

[rfoll]

https://www.summitracing.com/parts/pro- ... /chevrolet

[gmrocket]

https://www.summitracing.com/parts/pro- ... /chevrolet

thanks, we ordered the short version of that pump today..#68245

[gmrocket]

got it mocked up..spacers are cnc'd 3/8 thick. gotta make two round block off plugs for the timing chain cover. also made some thinner spacer plates for the water pump out of 1/8' stainless plate, but decided to go with the aluminum.

[gmrocket]

" lack of good manifolding for the Gen II LT1". That makes a good validation for the path you are on.

that, and not having to go with a complete retro fit hydraulic roller set up if using a gen 1 block. this is a low budget build so we're putting in a different cam and reusing the lifters.