General Motor Swap Questions

So, I will be replacing my sbc 350 in my 87 k10 here soon and I have some questions and concerns y'all may be able to help me with. I consider myself to be mechanically inclined as I've worked on old junk my whole life, but this will be my first motor swap, so I'd like any input from anyone willing to share some knowledge. Also, this is very long winded as I want to be thorough.

First, I plan to go with a blueprint crate motor that makes 390 hp and 410 ft-lb of torque. My first question is will the stock 700r4 handle this power. I do not beat on my truck as it is my daily for work and college, I do occasionally take it through a ditch or small mud hole but never anything serious no hard launches or hard pulls honestly couldn't see the motor ever going over 4k rpm with the way I drive it.

My next question is has anyone had any bad experiences with blueprint crate motors I plan on ordering it from summit it says it would ship immediately but some of the reviews say it takes months to arrive has anyone had any long waits with summit orders?

This swap seems pretty straight forward as I've worked on cars my whole life and the wiring is pretty straight forward. My plan is as follows drain all fluids, remove rad support and exhaust manifold, drop starter and pull carb off, remove all accessories, Mount engine to hoist, remove all engine mounts and bellhousing bolts, and pull motor. Is there anything I'm missing on the removal?

Next, I plan to reuse all accessories except the PS pump as the alternator and start are less than a year old, the carb is about a year old and the distributor is fine as well, the water pump is the only accessory I'm concerned about, but it would easy enough to swap if I do have any issues with it. Would it be a bad call to re-use the Dizzy and water pump?

I reckon it would be easier to install the accessories while the engine is on the stand is this accurate? Also, my plan for installation is just the inverse of the removal but I'll go through it just to be through. Place engine in bay put in the bell housing bolts and engine mounts, install distributor and carb, install exhaust manifold and starter, fill all fluids, go through break in procedures.

Another concern I have is in regard to the break in procedure. On their instructions it says avoid idling the engine during break in, but I would need to idle it to set the timing and the carb as it would need to reach operating temp to tune the carb. Am I just overthinking this could I run it through a heat cycle to adjust carb or should I just get it good enough. I'm pretty confident the carb would run good as soon as I slap it on considering it runs good on my current engine and the cam is pretty mild.

This ended up being much longer than anticipated however any knowledge or input would be greatly appreciated if I missed anything or if anyone has a better method I would greatly appreciate any and all advice.

Thanks in Advance

As long as the distributor and carb are tuned correctly there should be no issue using them. As far as the water pump, that’s a pretty cheap part. Unless it’s fairly new I’d personally replace it. It would suck to get the truck running well only to have it start leaking a week later.

As far as timing, once the engine runs, rev it 2500-3000, hold the throttle steady and slowly rotate the distributor until you find the point where the engine speed is the highest. Back off the timing just a bit and lock it down. That will be close enough for break in. Since the engine isn’t under a heavy load, you don’t need to be concerned with detonation. Once the break in is done, set the timing correctly.

If the trans is in good condition, it will probably last with the addition of a good shift kit and servo. While the valve body is apart, install new accumulator pistons and spacer plate, install the bigger boost valve mentioned in the shift kit.

These are roller cam engines, so cam break-in is not needed, and idling them is less of a concern. Just get timing and carburetor set well enough so it runs smoothly, and then start the break-in by driving at various speeds and rpm to seat the rings. Follow their recommendations for break-in oil viscosity, and plan for an initial oil change at about 500 miles. After that you can use a normal oil change interval.

I don’t know how well a stock 700R4 will hold up. The early 80’s version was found to have issues, and they were improved in later years. Maybe you can make some upgrades to improve durability.

75gmck25 said:

These are roller cam engines, so cam break-in is not needed, and idling them is less of a concern. Just get timing and carburetor set well enough so it runs smoothly, and then start the break-in by driving at various speeds and rpm to seat the rings. Follow their recommendations for break-in oil viscosity, and plan for an initial oil change at about 500 miles. After that you can use a normal oil change interval.

I don’t know how well a stock 700R4 will hold up. The early 80’s version was found to have issues, and they were improved in later years. Maybe you can make some upgrades to improve durability.

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I appreciate the info. I was considering doing an after market torque converter but I wouldn’t see that as helping all that much. They also make one with 341 Hp and 371 ft-lb would the 700r4 hold up better with this option.

I would budget a rebuild for your 700 trans in the near future. I guess we need to know how many miles are on it and was it maintained. You need to set the TV cable correctly after you get the new engine set. If you don't set it correctly, the 700 won't live long. If it has a lot of miles, you might get it to live a little while if you're really easy on it. If you have luck like mine it won't. I rebuilt the 6.0 in my 2500 at about 165K. The 4l80E didn't last a week! The shop told me they go out around 160-200K. Oh well.

Only thing I'd add (having done engine swaps but not specifically Chevy) is be prepared to deal with broken bolts and studs - may be less problematic since you're swapping engines but things like exhaust manifold bolts invariable break on removal - you'll probably need (or at least want to have on hand or at a good parts store nearby) replacements for any fastners that you'll need to re-use that may become unusable. Those nuts and bolts have been in place for 37 years, they may not take kindly to being disturbed at this point.