L29 454 swap

M

marauderprime

Apprentice
Jun 21, 2016
76
33
hey all, my name is Blake, and I have a 1984 Monte Carlo ss with a targetmaster 2pc rms 350 that was installed in 1986 under warranty, and the original th350c.
At some point in time somebody installed a 3.73 motive gear into the open carrier (and didn’t change the speedo gear), but with the tires I have on it, the car was turning 3500 rpms at like 65 mph.

I picked up the car this year for my birthday, and it’s my third Monte.
My original one had a Mike lis spec vortec headed 350 in it, originally with a 700r4, then later with an lt1 t56. I had that car from the time I was 15, until I went to grad school when I was 25. I ended up having to part it out to buy books for school.

I had a second one I should never have bought that I put a 5.3 in and hooked up to the stock th2004r, which it toastedin 2 weeks under normal driving, then I got married,it went to the bottom of the priority list, and Then the body rotted away. I ended up selling it for a song to a body guy that wanted a father son project for his son.

this newest one has a little rust on the drivers side (which I will head off at the pass ASAP) and some frame rot, which I will address by replacing the frame.

I was originally planning on canibalizing a 1986 corvette I had to bring this thing into a more modern state of being.
the 350 that’s in it is on borrowed time, and between what it is leaking and what it is consuming, I’m having to put 2-3 quarts of oil in it a week. Between that and the lack of overdrive, this Monte isn’t ready for prime time as a reliable daily driver.

then I stumbled upon grandprix454’s build thread. I loved everything about it. I’m going to make a few executive decisions on some stuff, but that swap accomplishes all of my goals with a few modifications. I’ll end up with a 1pc rms roller cam 4 bolt block. I already ordered an engine harness and a computer tune from Howell efi so I will be able to control the trans and maintain the sfi. I am running an electric fan, a Bosch 044 fuel pump, and the donor truck had a helper pusher fan, a very nice bar and plate auxiliary transmission cooler, it is set up for an oil cooler, which I have to figure out, as my Monte radiator doesn’t have provisions for an in rad oil cooler. Factory serpentine belt assembly, upgraded alternator, upgraded style a/c compressor, and the strongest automatic overdrive transmission ever to come from the general.

I ordered a set of cheapie mid length chevelle headers from speedway, 3” collectors with o2 bungs, and an egr delete plate. If this stuff arrives by Saturday, the next update should be the motor in the car ready for final hookups.
 

Attachments

M

marauderprime

Apprentice
Jun 21, 2016
76
33
I used Paul c’s thread on mcss.com to remove the front clip.

(We had a hell of a time pulling the bbc 4l80 combo as a unit, and prayed to the automotive gods incessantly while we were pulling because it was warping portions of the engine hoist, but it held. Pulling the front clip will allow us to slide the engine in with much less height.
 

Attachments

454GrandPrix

454GrandPrix

Master Mechanic
Jul 27, 2016
426
93
Lehi, Utah
I decided not to run an oil cooler--I simply plugged those outlets in the block. I don't have an oil temp gauge, but so far everything has seemed fine. Since the block is set up for it, I don't blame you for wanting to put one in. (I almost did.)

I'm happy to see you start this thread.
 
M

marauderprime

Apprentice
Jun 21, 2016
76
33
So I’ve ordered a Robert Shaw 180 degree thermostat from speedway that they drill the bypass holes in. I’m going to put a new water pump on it. I’m trying to decide between a Stewart emp aluminum and a flowkooler, so if anybody has any thoughts or advice on that choice, that would be helpful.

after reading a lot of the heavy duty truck forums it seems like the stock vortec puny 19 lb. injectors are garbage. I did a lot of soul searching and looking around at what my friends are doing, and I ended up calling Troy,Howell efi’s tuner, we walked through the tune and then I asked him if he could give me a performance tune with 80 lb. injectors, and he said it was no problem, so I had him do it, and then I ordered a set of 80 lb. ev1 injectors from vs racing. They have them for $335 for a set for the Siemens a deka injectors, so that will give me plenty of room to grow.
I also found out they didn’t have the harness in stock, so it hasn’t even gone out yet because they are building it which is fine.

this Sunday I will head back to my buddy’s house to tie up odds and ends. I need to pull the stock l69 harness and computer, finish removing the stock crossmember. I wasn’t able to get the last bolt because it was so corroded I couldn’t get a wrench on it and I was losing daylight, so I just jacked the trans up and swung the x-member out of the way so I could get the drivetrain out.
I’ll finish that, install the new g-force 4l80 crossmember, install my Bosch 044 pump and replace the stock crappy fuel lines with high pressure rubber fuel line (not ideal but temporary), pull the factory shifter assembly apart and see if I can get the stock 2500 shift cable to work somehow, and if I can get all of that done, then I think I can finish the install and have it running in either one or 2 more 8-10 hour days.
 

Attachments

L.A.X-RATED

L.A.X-RATED

Royal Smart Person
Aug 25, 2010
1,368
83
87 SS rust free patches,and rust free frame((bare)---747.29+ shipping."rolling with factory 373 posi,f41 suspension,and all around ls1-OR-zq8 blazer disc brake upgrade---1729.42+ shipping.pm me if interested.LOVE THE 5.0!!! do you own a maurauder?
 
M

marauderprime

Apprentice
Jun 21, 2016
76
33
87 SS rust free patches,and rust free frame((bare)---747.29+ shipping."rolling with factory 373 posi,f41 suspension,and all around ls1-OR-zq8 blazer disc brake upgrade---1729.42+ shipping.pm me if interested.LOVE THE 5.0!!! do you own a maurauder?
haha that’s my buddy’s 5.0. He’s the original owner. It’s a 1993 lx 5.0 5 speed, stock bottom end, ford racing f-cam Edelbrock performer rpm intake, cx racing single turbo 75mm bb turbo, tremec 5 speed, 03 cobra front brakes, 01 cobra irs. It’s pro toured up the wazoo.

I appreciate the offer on the frame, I already have an extra rust free frame I’m beefing up substantially, I also have zq8 spindles with more 3 brackets for c6 calipers, etc.

I was really into Marauders when they came out, I ended up getting a crown Victoria lx sport and spent the 8k I saved modding it. When I was done, there weren’t any N/A marauders that could beat me.
4C3288C5-6B02-42A4-B951-78147D03ABA1.jpg
 
S

Supercharged111

G-Body Guru
Oct 25, 2019
704
93
Why 80# injectors? Stock were 21 or 24 @ 4 bar. You should replace the FPR too, those were just as notorious as the stock junk injectors. You lose a lot of fine control with such big injectors. I have a Whipple on my L29 with a 320 overkill pump and 42# injectors and have fuel for days. If it's not too late, I'd recommend a much smaller injector. I used Series II 3800 supercharged injectors.
 
M

marauderprime

Apprentice
Jun 21, 2016
76
33
Why 80# injectors? Stock were 21 or 24 @ 4 bar. You should replace the FPR too, those were just as notorious as the stock junk injectors. You lose a lot of fine control with such big injectors. I have a Whipple on my L29 with a 320 overkill pump and 42# injectors and have fuel for days. If it's not too late, I'd recommend a much smaller injector. I used Series II 3800 supercharged injectors.
Well sir, you discovered my secret, but the first phase of this project is to get the car running and driving again ASAP so that I can finish up the a/c. I’m turning my attention to the chassis and suspension next, and once that’s finished, I’ll be adding a Borg Warner s480 1.32 a/r turbo
 
S

Supercharged111

G-Body Guru
Oct 25, 2019
704
93
Now that's more like it. 😎

I didn't see a mention of how you intend to tune. I recommend a 411 swap, I've swapped both of my trucks. You gain 2 and 3 bar MAP ability, MAP boost retard if you go SD, and a bunch of driveability with a custom operating system flashed on. FYI the plenum has to come off to swap MAP sensors, but really you should yank the lower too and do the intake gaskets as they're notorious for leaking. Unlike the small block though, there is no aluminum gasket upgrade available.
 
Last edited:
M

marauderprime

Apprentice
Jun 21, 2016
76
33
Now that's more like it. 😎

I didn't see a mention of how you intend to tune. I recommend a 411 swap, I've swapped both of my trucks. You gain 2 and 3 bar MAP ability, MAP boost retard if you go SD, and a bunch of driveability with a custom operating system flashed on. FYI the plenum has to come off to swap MAP sensors, but really you should yank the lower too and do the intake gaskets as they're notorious for leaking. Unlike the small block though, there is no aluminum gasket upgrade available.
so I’m getting an out of the box tune from Howell, but my plan was to either step up to the 0411, or a megasquirt with the turbo. One of the premiere megasquirt builders/tuners in the country is Jeff Linfert, and he lives in my town. I like that the megasquirt 3 has some pretty phoenominal self tuning capabilities, so once it’s in and dialed in, I can make changes on the fly, and just fire up tuner studio autotune.

I‘be been chatting with Dempsey for a few months now, and the general consensus is that when I swap the computer, I’m going to swap to the Holley single plane efi oval port intake with an accurate throttle body. I think the factory intake will be fine for commuting back and forth to work, and the occasional stoplight smoke show, but I’ve done too much reading on people who have spent a lot of time and money attempting to modify the intake and ending up with negligible gains, but I will be swapping out the gaskets.

what canI do for an upgraded fuel pressure regulator? That is one of my immedeate concerns, and I’m already pulling the upper to do the injector swap.
 
  • Like
Reactions: motorheadmike
Similar threads





Please support GBodyForum Sponsors

Classic Truck ConsolesDixie Restoration DepotMike's MontesP-S-TSouthside Machine PerformanceUMI Performance

contact[email protected]for info on becoming a sponsor