Engine swap diary

[Stewart G Griffin]

i will try to get some pics up asap, but i'm dealing with a lot of other stuff  (Hint:  Sprint customer service is not that good.........)

Installed brake booster vacuum hose/tube to back of carb.   v-6 tube is shaped different from v-8.  Fortunately the 4.3 came with this part when i bought it.

8 cyl Throttle return springs are too long.   Apparently on a 4.3 the carb sits further back in relation to the throttle bracket.   i'll try modifying/shortening the springs.

8 cyl air filter housing will NOT fit due to interference mostly from the top radiator hose.  It did clear the HEI distributor though.  i will look around for something that might work.

Can you explain how to adjust the downshift cable?   i read to lift the "D" button, move the thottle to WOT, and then push the button in.  But i'm not real clear.   Also can you explain the science behind it----because it looks like as soon as the throttle moves, the cable also moves (i don't have the slotted one, i have the clip on).   So as long as the cable reaches it's furthest point when the throttle is at WOT i'm good?

[enaberif]

For the transmission cable connect it all up.. lift up the lock tab.. have a second person get in the truck and push the pedal down to the floor and lock the tab.

[Stewart G Griffin]

As you can see, the 4.3's radiator hoses do bolt directly to the 8 cylinder radiator:





Thanks for the info about the downshift cable. i'll take care of it later as the truck will run without it.

[Stewart G Griffin]

3 torque converter bolts installed, engine-to-bellhousing bolts installed.

Trans dipstick installed---also bolts to one of the bellhousing bolts.  vacuum tube for vacuum modulator installed.

Throttle bracket installed.  Found the v-6 throttle return springs.  Pioneer Automotive products throttle cable  part#CA 8508 ill fitting and doesn't work very well.  Will need to find N.O.S. throttle cable on ebay (not likely) or custom make one.   Note that on 4.3's the carb sits further back compared to v-8's so i can't use the v-8.   Maybe i can somehow shorten it?

[Stewart G Griffin]

New Y-pipe for 4.3 and exhaust manifold installed-----decided to go with a stock Y-pipe and run a single flex pipe to a muffler for now to get it running.  Also, this makes it easy to drive to an exhaust shop.

[Stewart G Griffin]

Exhaust too difficult---can't get a good  secure seal between flex pipe and y-pipe using a band clamp.  Don't want to use a u-bolt clamp and i don't have any welding equipment.   Will drive to the exhaust shop with open flex pipe.   i have seen the videos on Youtube with 4.3 open exhaust.  It's not that loud.

BTW.  Walker Y-pipe for 4.3 v-6 into 85-87 trucks is part #40423

Next, on to power steering brackets.

Only a few things left, check oil , install spark plugs. i think i will hold off on new plugs for a while, fill radiator, get suitable air cleaner, instal egr valve, install a few vacuum hoses, get throttle cable worked out and we can get it running.

[Stewart G Griffin]

Installed starter and wires,  Starter front brace is interfering with the 4.3's strut rod bracket, so the starter will have to come back out soon.  i am just interested in getting it running for now.  i should probably remove these strut rod brackets as they are only maybe .025 thick.  i originally left them in because i thought it would affect engine positioning but when you think about it, not really.  Installed egr valve, installed plugs and plug wires.

i am mentally burnt out from working on the truck.  i would rather drive a car than work on it.

i think the only things left are:
Fill radiator

check oil (should probably be changed)

vacuum hose for trans modulator and torque converter lockup solenoid.

pcv hose  (engine originally came with 2PCV valves!!! One in each valve cover!! )

re-install breather for valve cover.

oil fill cap for valve cover

recharge battery

install alternator and belt

install power steering pump.  Need new P/S pump line and return line as this pump sits about 4.5" farther back than on a v-8 and the v-8 lines won't reach.  AC delco
still carries it for the 4.3,  part#36-356240  although i think it might be made by someone else.

reprogram tach for 6 cyls

install electric fan properly.  i'm planning on using one out of a 04 cavalier.  i don't tow or haul heavy so it should be adequate.

Find suitable air cleaner.  The stock v-8 air cleaner assembly won't fit

Throttle cable

[Irish_Alley]

best thing to do is take a break then jump back on it. i faced the same problem with my truck and many will lose interest in their projects when they get burnt out

[Stewart G Griffin]

UPDATE:  AC Delco P/S pressure line part# #36-356240 WILL NOT fit because the pressure inlet on the steering box for an 83 truck is 18mm.  Apparently, by 85 all steering boxes for the trucks went to 16mm opening.

i ended up using the v-8 high pressure line and pivoting it differently so it would reach.  Installed longer return hose.

Alternator and negative battery ground cable installed.

[enaberif]

You keep saying the air cleaner won't fit. What doesn't fit and why? If its because of the upper radiator hose go pickup a air cleaner spacer and bolt it up.

http://www.summitracing.com/int/search/product-line/mr-gasket-air-cleaner-spacers/

[Stewart G Griffin]

You keep saying the air cleaner won't fit. What doesn't fit and why? If its because of the upper radiator hose go pickup a air cleaner spacer and bolt it up.

http://www.summitracing.com/int/search/product-line/mr-gasket-air-cleaner-spacers/

The stock v-8 air cleaner housing won't fit and i think it's interfering with the brake booster vacuum hose bracket and it may also be interfering with the rad hose.  Carb for a 4.3 sits further back in relation to everything compared to a v-8.

i may try the spacer.  How will this affect airflow?

[Stewart G Griffin]

Finally got power steering pump mounted and a belt that fits   (Dayco 15445 which fits around the crank, water pump and P/S pump only.)

Alternator belt and wiring hooked up.

ground strap to head connected.

PCV hose connected.

Tach reprogrammed for 6 cyls.

i tried starting it up and no spark---verified thru in-line spark tester.  Also no rpm signal at tach.

i'm tempted to go the dealer and sign on the dotted line;  i see a new Colorado can do everything this truck can do---AND get 27mpg.

[Irish_Alley]

are you getting 12v to the distributor?

[Stewart G Griffin]

Not sure how to check?

[Irish_Alley]

on the distributor you should have 2 different plugs one goes to the first 3 wires closest to the distributor and the other goes on the outer post of the distributor marked "BAT" right next to the "TACH". verify  its plugged in and youre getting 12v to the "BAT" plug wire (should be red)