6SpdLT1Z

Hey all,

Hoping to start piecing together an engine for a mild 350/355 build. Looking to put out 400rwhp-425 when all is said and done. For the initial build, I'll most likely go cam only just to get it in sooner then I'll look at getting the heads re-worked (AI 190 or 200cc?) to put me over the 400hp mark. Planning for 350-375rwhp cam only.

Now onto the question at hand. I'd LIKE to get a 4-bolt block, but I feel like I'd be okay with a studded 2 bolt. What I'm looking to do is find a pretty complete motor that will almost swap straight into my 1997 SS. This is simply downtime when the day of the motor swap comes. The build will be done slowly, but I'd like to minimize swap downtime so that I can actually enjoy my car during the summer.

So, anyone want to help me figure out what I should be looking for? I'm assuming I'd want to find a 96-97 motor.

• 96+ OBD-II
• 95+ Vented Opti/Timing Cover
• 96+ Crank Sensor
• 94+ Intake Manifold (fuel rails)

Along with these differences, if I bought a Corvette block I'd need to put a Camaro front drive system and water pump on it, correct? And yes, I know there were a few f-bodies built with 4 bolt blocks.

Also are there any key differences between the 10128649 heads and the earlier castings? Keep in mind I will be going through this motor and rebuilding it but the closer to a direct swap the less I'll need to buy. I'm not in a huge hurry to find the donor motor.

RamAir95TA

First things first. What is wrong with your current block? If there's nothing wrong with it why not just get the heads/cam now and run it? You'd EASILY see that goal of 400-425whp.

In terms of differences in the block itself there are none (aside from the 4-bolt Corvette blocks and the 4-bolt replacements). All blocks are interchangeable.

If you are looking at the AI heads they MUST be the 374s or 643s. The later castings (supposedly) do not work with their CNC programs.

Most of the parts on the new motor can use your old existing parts. I would go this route because you at least know those parts work. Picking up an unknown motor and using its accessories may come with unknown problems.

6SpdLT1Z

This will be a pretty slow build process, I'm not looking to pull the motor out of my car for 2 years and let the car sit. I'd be better off selling it and buying a LS1 Corvette.

I'm not looking to build on my current motor, I don't feel like spending $1500 on a cam swap to find out I spun a bearing or whatever. There is nothing wrong with my current block, but I'm not looking to use it as I plan on keeping it in my car and enjoying it until the time comes to swap.

I realize that I could reuse a lot of my parts, and parts that are difficult to replace that I may not know work (such as opti/waterpump) I will consider replacing. If the alternator doesn't work that won't be hard to replace once the swap is done.

Guest47904

I understand you want to drive the car while you build the engine. I had started down the same path but because I did it with individual parts, it took too long, cost way too much and I lost interest.

The path's you follow to get to the end vary greatly and have more or less headaches also. I don't recommend you buy individual components and try to make match up and work. Balancing alone can be very expensive. I made that mistake.

You could get a block and buy a balanced rotating assembly. However if you look at something like this linky Look near the bottom of the page at the ultra economy 355
While it may not seem to be a cost effective choice up front. It is when you get done.

You would have to find a block, get someone to clean, machine and install cam bearings for you. If the block has a problem, you may have to start all over. Then purchase the rotating assy. By getting a pre-assembled unit like this, you eliminate a lot of headaches and cost will be the same or less as doing it all your self.

Been there and I know.

6SpdLT1Z

Well.. my problem with that is it's only a shortblock.. and.. there are unnecessary costs built into that.

I have built a SBC 355 before, so I know how to check crank clearance, etc. The stock LT1 rods and crank should be fine for my power goals, and I will absolutely have the block checked out and balanced by a reputable engine builder in my area.

Honestly there isn't a lot that needs to be changed in my motor to make my goals but it does require the motor to be pulled and disassembled, so ideally i'd rather find a decent longblock, freshen it up with a few more goodies then swap it in. Even if I were to blow up the new block atleast I'd have a reliable motor sitting in the garage that I could swap back in.

I think Joe's post in my earlier thread is pretty close to my plans, except I plan on freshening up a different motor than what is currently in my car. Like I said, I'm only shooting for ~375rwhp (cam only) or a little over 400 with some heads. We don't even have a race track anymore (closest one is an hour a way) so it will be 90% street and it isn't my daily driver. That being said I do enjoy driving it so I'd like to be able to pull it out of the garage anytime I want, hence my intentions of minimizing downtime.