427 SBC & 4L80e build

[72K5CSTDarkOlive]

I'm replacing the engine in trans in my 72 K5 and decided on a 427 Stroker mated to a 4L80e.

I'm using a local shop (Gromm Racing Heads) to build the engine and another local guy to build the 4L80e.

The parts for the build we are going to use are the following:

Block: New Dart SHP 400 Block w/350 Mains. 4.125 Bore, 2 pc rear main
Crankshaft: Dart 4340 Forged for Internal Balance
Pistons: Mahle Forged Pistons
Connecting Rods: SCAT Forged
COMP Custom Camshaft: TBD...I know that it will be around .600 Max lift and the duration will be somewhere in the ball park of 243-258 @ .050. The Lobe separation is 110-111.

COMP Full roller stainless steel 1.6 ratio
(EDITED) AFR 220 CC Eliminator heads, 2.10/1.6, 65 CC
(EDITED) Edelbrock Super Vic
MSD Pro Billet Distributor
(EDITED) Holley Sniper
Headers: Kooks 1 7/8" stainless steel

The Command Center will let me use my existing electric fuel pump and I am building a return line that will go back to gas tank through the sending unit.

The 4L80e will be updated with the 32 spline input shaft to connect to the 205 TCASE and he is building a billet tq converter using a 2500 stall.

These arrived this week and my builder is going to get going on this for me.


Updates as of 8/1/18: So I changed a few things on this build setup. I'm not going to use the FiTech and instead going with the Holley Sniper. I also wont be running their command center 2. To run the EFI I am using a Boyd Welding EFI tank that comes with a in-tank Aeromotive fuel pump.

[Blazerowner]

I just put a 4l80 in my 72 K5. The output is 32 spline stock but you have to make sure it is the correct shaft. It has to be fully splined so you can cut it to adapt to the np205. I kept mine in the stock location. It put the engine forward a bit as it’s a long transmission.

[72K5CSTDarkOlive]

Originally Posted by Blazerowner

I just put a 4l80 in my 72 K5. The output is 32 spline stock but you have to make sure it is the correct shaft. It has to be fully splined so you can cut it to adapt to the np205. I kept mine in the stock location. It put the engine forward a bit as it’s a long transmission.

How do you like the 4L80e? Did you use a single or triple clutch?

The guy that's building has done this swap many of times on our Blazers. I just couldn't remember all the details he went over with me to make it work and support the TQ my engine is going to put out. I'm going to try my best to document the entire build so others can reference it if needed.

We're going to keep the engine in the stock location and move the tcase back and use a custom driveshaft.

[kwmech]

I've been looking at buying the same Dart block for my Suburban.......... going to follow this build. I know the casting is heavier, but any idea of the amount of bore left with the 4.125 hole?

[72K5CSTDarkOlive]

Originally Posted by kwmech

I've been looking at buying the same Dart block for my Suburban.......... going to follow this build. I know the casting is heavier, but any idea of the amount of bore left with the 4.125 hole?

I'm going over there today and can check.

[72K5CSTDarkOlive]

The block came in undersized @ 4.110. He's going to bore it .010 and hone the last .005

[DeadheadNM]

On board for the build...

[72K5CSTDarkOlive]

So I found out the Dart 400 block can be bored up to 4.200. So the 4.125 will leave us .075 for future rebuilds.

Decking it tonight when the temp drops. It's been really hot these last few days. Tomorrow they'll do the internal balance and finish up the rest of the block work by the end of this week.

[72K5CSTDarkOlive]

With the big cam I'm going to have to convert to hydroboost. Got a set of brackets for the hydroboost from CaptainFab. The hydro unit came from Power Brake Exchange here in San Jose. pwrbrake.com

This particular unit came off a 90's P30 Chevy Step Van. For the MC I needed to step up to a 1 1/8" bore. Everything looks to line up perfectly.

[TexasT]

Originally Posted by 72K5CSTDarkOlive

With the big cam I'm going to have to convert to hydroboost. Got a set of brackets for the hydroboost from CaptainFab. The hydro unit came from Power Brake Exchange here in San Jose. pwrbrake.com

This particular unit came off a 90's P30 Chevy Step Van. For the MC I needed to step up to a 1 1/8" bore. Everything looks to line up perfectly.

What made it need to a 1.125" bore on the mc? Rear Disk upgrade? I love the hydroboost set up. I think they work great on my stuff, though I just used stock stuff on mine.


That bare block is SEXXY!

I'd like to know the particulars of the 4l80e build also. Did the tc just require a new 32 spline input? I know that is what I did to the np246 I put together for our Burb when the pump rub took out the original.

Great build! Keep On Keeping on. My neighbors would be having a coronary if I had our truck on stands for more then an afternoon.

Looks like they dynoed with a carb? Timing stated to be 40*. Is this locked there or are you running a dist with vac advance and mech advance or one? I'm no guru but the bsfc looks low and the engine might could use some tuning to get more out of it. Either way it DEFINATELY makes PAH! Will they be making any pulls with your fuelie setup?

Originally Posted by DeadheadNM

Too cool! Did you have to update any of the parking brake cables for use with the rear disc brakes? What happened with the OEM fuel tank - available?

I think this guy wants to acquire your original tank.

[72K5CSTDarkOlive]

[QUOTE=TexasT;8336265]What made it need to a 1.125" bore on the mc? Rear Disk upgrade? I love the hydroboost set up. I think they work great on my stuff, though I just used stock stuff on mine.

I was told that the bigger bore would give it more pedal travel but less pedal effort and I also think too because I'm doing disc/disc. It was a recommendation from the place I got the Hydro unit from.


That bare block is SEXXY!

I'd like to know the particulars of the 4l80e build also. Did the tc just require a new 32 spline input? I know that is what I did to the np246 I put together for our Burb when the pump rub took out the original.

Great build! Keep On Keeping on. My neighbors would be having a coronary if I had our truck on stands for more then an afternoon.

Thank you! Luckily, I was able to get the trans/tcase installed that same day. I went to Harbor Freight and picked up a transmission jack to do the install. I put it back in the box very neatly like no one ever used it and returned it that same day.

I'm waiting for the guy who built my trans/tcase to get back into town. He's been out of the country for a few weeks. I'll make sure to get all the details that went into the build and update this thread when I do.

Looks like they dynoed with a carb? Timing stated to be 40*. Is this locked there or are you running a dist with vac advance and mech advance or one? I'm no guru but the bsfc looks low and the engine might could use some tuning to get more out of it. Either way it DEFINATELY makes PAH! Will they be making any pulls with your fuelie setup?

We had to use a carb because we didn't have an EFI pump that would have been sufficient enough to use at the dyno. The distributor is mechanical advanced only and is not locked out. It comes into total timing around 2800 rpm and when the dyno is testing (starts at 3500 rpm) it's already fully advanced.

My engine builder thinks we could get more out of too because it was running a little more on the rich side and if he had some more time he could have leaned it out a bit. The Cam has 4 degrees advanced built into it to help with the bottom end so if we didn't advance the cam we definitely could have picked up more on the top end but I'd rarely ever take advantage of using that power at 6500+ rpms.

A chassis dyno might be in the foreseeable future!

[DeadheadNM]

Too cool! Did you have to update any of the parking brake cables for use with the rear disc brakes? What happened with the OEM fuel tank - available?

[72K5CSTDarkOlive]

Originally Posted by DeadheadNM

Too cool! Did you have to update any of the parking brake cables for use with the rear disc brakes? What happened with the OEM fuel tank - available?

Hey Pete - I lucked out on the parking cables. They just happen to be long enough. I ordered the PB cables through Wes and they came from Inline Tube. I couldn't tell you the actually length of the cables.

Not sure I understand your second question. After researching my options to run EFI, I felt the Boyd Welding tank was the best and less complicated option.

It comes EFI ready with an Aeromotive in tank pump, sending unit, return fitting and proper vent fitting. The filler neck extends right over the frame rail and sits a few inches under the truck bed. I had to add a new post filter to handle the PSI from the EFI. I mounted the filter inside the frame.

Other options would have been the following:

1. FiTechs Command Center - This acts as a remote fuel pump and it's pretty big in size ( not something you could really hide in the engine bay) It does allow you to run your existing fuel delivery system.

2. Drill into my tank and install Holley retrofit in-tank pump. I would've had to buy a new OEM tank just to do this. I guess I could have drilled into my current tank, but that doesn't sound sketchy at all... (the cost of this setup would have been almost just as much as going the route I did.

[72K5CSTDarkOlive]

Short Block is assembled.. Now we are waiting for the heads to be built from AFR. We have to go directly through AFR because of the custom springs. They take 3 weeks for them to build. Strange that they don't have a set sitting on the shelf, especially for SBC.

[Rickysnickers]

I have an engine question. Since that's an aftermarket block, are there steam holes in it or not? I'm not familiar w/where they would be located which is why I'm asking, in part. Thanks.

[72K5CSTDarkOlive]

Originally Posted by Rickysnickers

I have an engine question. Since that's an aftermarket block, are there steam holes in it or not? I'm not familiar w/where they would be located which is why I'm asking, in part. Thanks.

The steam holes are similar to a sbc gen 1 350. They are not like the 400.

[nautique1228]

Looking good, contemplating a similar build for my 58. 408 Stroker LS, with ls3 heads and edelbrock super victor intake. Are you planning on staying all motor? What power level or E.T you looking for?

[72K5CSTDarkOlive]

Originally Posted by nautique1228

Looking good, contemplating a similar build for my 58. 408 Stroker LS, with ls3 heads and edelbrock super victor intake. Are you planning on staying all motor? What power level or E.T you looking for?

Yes, for now. Shooting for 600+hp and 575+ TQ. The custom solid roller my engine builder is using should easily exceed this. We actually might have to tune it down a bit. The Holley sniper I am using is rated up to 650 HP.

[nautique1228]

Solid roller! That’ll be a bad sob!
Posted via Mobile Device

[72K5CSTDarkOlive]

Originally Posted by nautique1228

Looking good, contemplating a similar build for my 58. 408 Stroker LS, with ls3 heads and edelbrock super victor intake. Are you planning on staying all motor? What power level or E.T you looking for?

Check out this 408LS that they are building right now too.

[jjzepplin]

WOW! Them parts are purdy! I'm In.

[YoungPup1977]

All them engine parts for that there horsepower. Can’t wait to see how the trans is going to be built to withstand all that power and how you plan on putting all that power to the wheels.
How about some pics of the parts installed into the trans and how the trans was upgraded to withstand 650 HP thru the NP205.
Posted via Mobile Device

[72K5CSTDarkOlive]

Originally Posted by YoungPup1977

All them engine parts for that there horsepower. Can’t wait to see how the trans is going to be built to withstand all that power and how you plan on putting all that power to the wheels.
How about some pics of the parts installed into the trans and how the trans was upgraded to withstand 650 HP thru the NP205.
Posted via Mobile Device

I specifically told the guy who was building the trans and Tcase to only handle 400 lbs of torque.. Dude, go troll somewhere else.

[YoungPup1977]

Originally Posted by 72K5CSTDarkOlive

I specifically told the guy who was building the trans and Tcase to only handle 400 lbs of torque.. Dude, go troll somewhere else.

Ok. I’m gone

[72K5CSTDarkOlive]

Originally Posted by YoungPup1977

Calling me a troll ? WTH....the thread name includes a 4l80e build too. Just wanting to see pics of the trans build. Oh I see you are only a check writer.... sorry DUDE my bad............
Posted via Mobile Device

Originally Posted by Rickysnickers

I don't think he was trolling you. It sounded like a legit question to me.

It was a legit question but I felt it was asked in a condescending manner. At least thats how I interpreted it, but maybe that wasn't your intentions so my bad.

I'm more than happy to answer questions and or provide detailed pics. I''ll be getting some pics and part #'s used next week and will post that once I do.

In the meantime, i'll try to answer your question. I sourced a 4l80e from a 2005 3/4 ton Yukon for 200 bucks. I took it to the guys shop who was going to build it for me to be able to handle the added power as well as go through the TCASE.

I know one thing we had to do was upgrade the input shaft from the 27 spline out of the Tcase to a 32 spline as well as an adapter plate. The internal shaft in the transmission he used is rated for up to 800 lbs of torque which I think it was a billet shaft, but I'll find out for sure soon.

For the torque converter I went with FTI's 3200 stall triple disk billet so the tuner can make adjustments to lock up sooner if need be.

As for writing checks.. Yes, for 400 bucks in labor I had an expert go through the transmission and use parts that would need to be upgraded. There was also machine work that needed done in both the tcase and trans ( more on that once I get the details) and for one, I don't own that kind of machinery to do that kind of work. For me, the 400 bucks in labor was worth it and I can go to sleep at night knowing it was built right and he will stand up to his work in case something happens.

Where I save money is doing the install and relocation of the Trans/Tcase myself. Having a shop do that would cost me more for this part than the actually rebuild. There are certain things that are far beyond my knowledge or expertise so I will outsource that, but I try to do as much on my own as I can or at least attempt.