hey guys, i'm new to the board

i just picked up an 87 iroc with no engine or transmission, it previously had a 5.7 tpi w/ automatic transmission

i'm planning on dropping in a carb'd 350 because the wiring was all hacked up, plus is just much more simple.

i need to know if any 4-bolt main 350 will fit? and will there be any typ of clearance issues with the oilpan or anything? any info about this would help a lot

also is there is any problems i might come across when dropping a th350 in?

thanks for any help

 

Since you will be replacing both, basically any 350 will fit. 2 pc or 1 pc RMS. LH dipstick, RH, it doesnt matter. Just make sure you have the right starter/flexplate combo. Seems to be one of the biggest problems people run into piecing together a driveline.

 

thanks for the quick reply

which starter/flexplate combo should i be looking for?

 

Find a block first. The size pertains to either the 1 or 2 pc rear main seal.

 

do i have to change the gas tank too? or can i modify it some way to make it work?

 

You don't have to change the gas tank. You should either wire up the in-tank electric so it works (with a return-style regulator at the carb), or drop the tank and eliminate the in-tank pump.

 

what if you don't install a return-style regulator. what if you just put in a regulator that only allows 6 or 7 psi? I have seen some that will let you do that but there is no return line for the tank. what would it do?

 

A deadhead regulator will cook an electric fuel pump.

 

thanks for the info guys

i might have some more questions later as the swap goes on

 

You will run into a problem when installing a th350. First there is no place to mount the torque arm so you will have to buy a changeover kit, and the driveshaft (which you probly dont have) will need to be 3 inches longer than the stock one.

 

where can i get this 'changeover kit'? or could i use something from a different 3rd gen?

also i figured there would be issues with the driveshaft, thanks for the heads up

 

anymore info you guys got would be great, keep it comin

 

You can get a B&M bracket that bolts to the tailshaft housing from Jegs or Summit.

Our sponsor Spohn (button above) has a nice kit that relocates the crossmember, and mounts the torque arm to it instead of the transmission. Much better arrangement.

 

If you go to the trans forum you can search and find a link to several threads detailing the conversion. I went with a kit that installs a 700r4 output shaft and tailshaft onto a 350 trans. Everything stays the same then: torque arm, speedo, crossmember, etc. Its a decent kit at a decent price too.

 

so i searched and read about the swap in the transmission forum,
many of the threads talk about switching tails shafts to reuse the current driveshaft, i currently dont have a driveshaft so getting one made to fit isnt a problem.

i'm still a little confused about which kit to buy to mount the th350 to the stock crossmember, do i get the b&m conversion kit pt#130-30299 or can i just get a 9" tail shaft and that'll solve the problem?
or is this totally wrong?

 

i'm guessing thats totally wrong, can anyone help me out here?

 

The 9" TH350 tailshaft housing makes the transmission the same length as a TH700.

That only solves the driveshaft issue, not the crossmember issue.

 

ok thanks

 

ok got the b&m kit, ready to do the install, i need a new tranny mount though.
what mount would you guys recommend? energy suspension?
a part # would be great

thanks

 

I put in an energy suspension tranny mount and couldn't be happier. It is able to take the torque and the shift kit with no problem, I ripped the stock one to pieces because I didn't change it when I swaped everything else over. I am not sure of the part number, but they make a universal one that covers most GM models, which is what you want. Also, if you put an energy suspension tranny mount in, you should consider changing the motor mounts to polurathane. I have heard if you do not do this either the new tranny mount or the old motor mounts can tear pretty quickly as they do not move the same amount, and seeing as you have the motor out already, a couple of hours of work is worth it now.

 

i finally got the motor, tranny and driveshaft all bolted up.

now the next step are the fuel lines,

how to i wire up the in-tank fuel pump to work with a regulator?

i was thinking about using a Mallory 3-port fuel pressure regulator and then run a line from the regulator to the carb, how does that sound?

 

nevermind

 

i need to know if i have to run new wires to the starter?
or which of the old wires i need to splice or connect to

 

i need help with the wiring guys, can anyone help?

 

if i rember correctly all red wires with large rings go to batt post along with batt cable. then there should be a pink wire that comes from the ignition switch to the solenoid. wire should have 12v with key turned to start.

 

the problem is all the wiring was cut off with about 6 inches left going into the plug near the master cylinder, so there are no wires with rings on them.

i need a pic or a diagram of the harness to identify which wires is what

 

Do you a Chilton's or Hanes? They have wiring diagrams in those by the year of course, however I have to stare at them for hours to understand what I'm looking at, but that's just me. You also may be able to do a search of this site or on the web for a wiring diagram. Good luck.

 

if you can wait till tonight i can look at my 87 harness and tell you what i used. you are going carb and hei ? i found wireing diagrams years ago by doing a google search.

 

i dont have a Chilton's or Hanes but i can get one from a friend,

SPIKE it would be great if you could take a look at your harness or find that diagram for me. and yes i'm going carb and hei

 

ok i downloaded my diagrams from fl-thirdgen.org. heres what i used.
harness by brake booster :
reds: to +12v, to feed fuse panel
pink: to dizzy +12v
white: to dizzy tach
purple: to starter solenoid
these are all you need at a minimum to get it running you might have to branch off to power other stuff fans,fuel pump ect. depends on your setup.i kept it simple and went with flex fan and mechanical fuel pump.
the other bulk head by booster has your wires for lights blacks,greens and such, let me know if you need any more.

 

from the harness there are 2 or 3 larger red wires coming out, which of them go to the starter?

 

reds to battery or get a post so you canrun many things from the post and only one wire to the battery, he said purple to small term on starter, big red wire from batt pos. to big term on starter. that sould be all you need. run a big ground from engine(i hooked mine to the alt bracket.)to the battery neg. also a big cable to body from neg.. make sure you clean to bare metal for all grounds.(very important) connectet then spray with paint to rust prevent.

 

finally got the motor cranking, thanks for the help guys

but my in-tank fuel pump isn't turning on, the fuse is good.

where do the wires run from the fuel tank? what could the problem be?

how can i check if the pump is any good?

i'm totally lost here

 

You have a fuel pump relay that should be checked. Also, if it is VATS equipped, and the key resistance isnt the right one for the car, the pumps wont come on either.

 

the wires go through the body at the back of the hump in the middle of the back seat. the computer used to turn the pump on. now you are going to have to turn it on yourself. there are many ways to do this. i like a switch to the relay but there are others that disagree.

 

ya i figured it out, thanks anyways