6.2 NA Build - Changed plans... again.

[jmack91z28]

Well I kinda changed up again on a 6.2 project. I've got the engine and 4l80e sitting around. I gotta do something with them. Still got the 96 gmc for sale... someone please buy it.

Bought a 91 Suburban, GMC. V2500 4.10 gears NP241 350 tbi and TH400.

I want to replace the driveline with my 6.2/4l80e. Already got the 6.2 stripped down to the longblock. Been doing a lot of research and gathering up pricing and details. Talked to bill the other night about his NA-66 cam setup.

Plan so far is: Bills cam and springs, rebuilt DB2 .29 IP, have the bosch injectors rebuilt, new bearings, gaskets, timing set, fluidampr. Everything else stock.

4l80e I'll have my transmission guy freshen it up and swap out the output shaft and tail housing to bolt to the 241 transfer. Have the driveshafts resized. Already talked to Leroy about the tcm kit he sells.

I'm going to changed out the brake system for hydroboost. Can do it all off of rockauto for about $450. That's booster, master cylinder, hoses and power steering pump.

New fuel tank, sender, frame mounted lift pump, lines and fuel filter setup. New engine oil and tranny coolers + lines and fittings.

Then all the misc stuff like wiring for GP's and a second battery. I'll worry about A/C later.

 

[jmack91z28]

 

[3500GMC]

91 blaziod, cc and 'burb is the last of their breed.

Always liked those trucks, even back to '73.

 

[countryboy69]

How are you gonna control the 4L80E?

 

[ak diesel driver]

in the first post he states "leroy's TCM" which is optishift.

 

[jmack91z28]

in the first post he states "leroy's TCM" which is optishift.

Exactly. I've read good things about them, not just because one of our site vendor sells them either.

 

[jmack91z28]

I've got the block basically stripped down. The big thing is I need to find a decent machinist who half way understands these engines.

I'm thinking just get the block cleaned and magnafluxed. Same with the heads too. I'll probably run a dingle berry hone down the cylinders before reassembly.

 

[countryboy69]

Hmmmm gonna have to research that! Gotta beat my toggle switches!

 

[jmack91z28]

Haha yeah, I'd imagine so. If anything the convenience will be worth it.

 

[EWC]

You got a 91 with a TH400 ? How did they run the speedo ??

 

[just a number]

the burbs stayed with the older mechanical speedo until 92 when the body changed. not much difference. from 87-91 parts wise

 

[EWC]

No they didn't . Late 88 into early 89 brought in the electric speedo , this was when the body designation was changed from the CK to the RV series . 91 was the last year for the square body and the first year for the 4L80E in the 3/4 and 1 ton models . Just rebuilt my 91 4L80E in the my R2500 suburban , have harnesses for a 91 3500 6.2/4L80E with the TCM and these are somewhat hard to come by . Code on the glovebox reads MT1 : 4L80E .

 

[jmack91z28]

Yeah my TCM and harness is from a 93 model 6.2/4L80e. I'm not going to use it though since it was out of a P30 van.

I'm really not sure what speedo it is, that's something I'll need to figure out soon too. I would imagine electric, but I'm not sure.

I apologize, I'll change the original post. My burb is an 89 model.

 

[just a number]

well I stand corrected. I didn't realized they had made a electric version of it. it ran from 88-90. my guess is the 4l80E was the replacement in 91.

what year is the 4l80E?

 

[EWC]

Hold on , you have 4WD so the transfer case has a sensor ( TOSS ? ) in the rear that should drive the speedo . Easy way is to look for the cable .
I have a few harnesses for my swap and noticed that in 87 they went to a smaller terminal end for the firewall connector which allowed some more wires in the connector . This was the same year for TBI . I have a harness from a 95 G van and that actually looks like it would work fairly well without hacking on the wires so don't dismiss the P van harness just yet . Be careful with the TCM as that is good from 91-93 and then they went to another number . Bobbie Martin did a book on replacing a DS4 with a DB2 pump and I think he covered this .

 

[jmack91z28]

well I stand corrected. I didn't realized they had made a electric version of it. it ran from 88-90. my guess is the 4l80E was the replacement in 91.

what year is the 4l80E?

93 model.

 

[just a number]

93 was the updated year. 91-92 has the old style plug in(bolt in center)

 

[just a number]

so you got the best of both worlds then. mech. IP and updated transmission.

 

[jmack91z28]

Just a number, I believe you are right. I crawled underneath the burb last night and it appears to have a mechanical speedo coming from the transfer case. Output side.

 

[jmack91z28]

Finished stripping the engine down last weekend. Got the heads disassembled as well. Bosch injectors on the engine too. So I have two sets of bosch's to send off for rebuild now which is good. I'm going to drop it off at a machinist tonight and have him hot tank it and mag it.

I need to get the ball rolling on the transmission. Also need to start looking at buying up all the rebuild materials and a cam from Bill.

Cylinders and bearing were in good shape. Hardly any lip at all had built up on the cylinder wall.