Swap 99 Vortech for 88 TBI - help please!

[oldchevynut]

Hi Everyone -
I know I am doing this backwards from what everyone suggests, but I have a 99 4x4 suburban with the vortech 350. I am wanting to swap it for an 88 tbi motor. (I need the truck on the road and I already have the motor and not much money). Has anyone done this type of swap? Any reccomendations on how to do it. Both engines are complete, didn't know if I could just swap the heads and intake from the 99 motor to the 88 motor or if there was a way to run the 88 motor like it is. I know the computers are different as well as many other things. Any advice would be greatly welcomed!

THanks,
Scott

 

[kd7kmp]

Check with you local DMV first to see if this swap will be legal. In many states, it is not legal to swap in a motor that is older than the vehicle. The motor must be newer than the vehicle.

Kevin

 

[oldchevynut]

Thanks for the tip Kevin. My state pretty much does not care. We don't do emissions testing, vehicle inspections, safety inspections or anything of the like. It's kind of crazy actually!

 

[FatHarryPotter]

what wrong with the 99 vortec 350. and yes my mom lives in taos and it is dam scary to see what some of the people will drive around.

 

[oldchevynut]

Over the past couple of years have had a lot of problems with the 99 motor. Have had the intake gaskets done twice, had to have the heads welded and machined due to 3 cracks, and various other small problems. All in all have spent over 2k on the engine and I could have replaced it for that. For about the past year it has suffered some power loss and a horrible hesitation under load. The whole truck starts jerking almost like the tranny is slipping. I replaced the plugs and that helped for a week making me wonder if it is not ignition related. Have replaced the 02 sensors, the MAF sensor, and one other one, it escapes me right now. On top of the hesitation, I have developed a bottom end knock - sounds like main bearings for about 2 seconds after a warm start. I still drive it 85 miles to work every day but I don't know how long it is going to last. Has 157k miles on it, which in past experience doesn't bother me on this engine, I've put over 300k on some, but this one is starting to get costly.

 

[FatHarryPotter]

wow that sucks. My father has a 99 with a votec and the thing still runs great.got about 120k miles. What is the running temp? As i have read chevy engines are designed to run hotter. several people have had some of the simptoms you have descriped because of the temp was set to low on the thermostate. as for the knock are you sure it the low end? when you unfortunally had to pull the heads how did the cylinders look? for replacing the plugs sounds like there might be some build up in the cylinders that why i am asking about the thermostate. Of coarse if you find out the mains are going then definently swap. Are you dead set on a 350 tbi? I dont know about the computer and and possible the tranny cause they have gone to computer controlled(no experience there). But you already have the right fuel tank so as far as i can see the only hich in swaping in a tbi 350 would be the computer. Since you are in NM the easiest thing would to just go with a old school carb bare bones 350 but again the tranny might stil need a computer so not sure. Atleast you have plently of options and arent fighting regs like people in ca.

Edit is the 350 tbi complete with computer?

 

[63chevyll]

wont work with the vortec injection, the vortec injection needs a crank sensor in the timing cover.....all 96+ blocks are different than tbi blocks.

now if yoy want to rig a tbi engine go ahead, but its like going backwards in time,

i would just put the correct engine, but just my opinion

 

[oldchevynut]

I'ts running probably about 195 on the temp. The cylinders looked ok, back one on pass side looked the worst, but still not bad, that is the one by the biggest crack. Originally pulled the heads thinking i had a blown head gasget but turned out to be cracks. Oil pressure runs at about 20 lbs at idle to about 40 lbs driving which is lower than my other ones. I'm not dead set on tbi, I just need to keep my suburban going. I guess since the 96+ blocks are different I couldn't get a target 350 from GM and just change the intake and heads like someone else told me I could either. As far as the knock goes, i'm sure it is the bottom end. It doesn't seem to be getting any worse, but no bottom end knock is good! The hesitation problem has been stumping lots of people around here, have had several mehanics look at it also as well as 2 GM dealers. They all keep saying 02 sensors or MAF. Have replaced both, twice. SES light is on and will go off in a few weeks and then come on again but doesn't pull any codes. We got one exhaust pressure related code one time, but has not returned. Running fairly new exhaust with factory cats going into a magnaflow muffler with a 3 inch tailpipe. Have had no exhaust issues and have been running this exhaust since before problems started. Also running K & N air intake system.