Vortec 350

[a.boddie.matthews]

Hi, Im new here so bear with me.
Just bout a 1988 chevy monte carlo. It has a 305 in it right now. I also have a vortec 350 thats getting ready to go into the machine shop that came out of a wrecked tahoe that I own. I would like to turn this thing into a 383. Do the same basic rules apply for the vortec 350 as it would for a pre 80's block, 400 crank rods etc???

I have an intake from edelbrock to convert from TBI into carb. I shouldnt need any stock sensors, or computer from the tahoe should I? What kind of problems will I run into with this builld?

Also the transmission was good. Its a 4l60e. what kind of challenges will I face in installing this into my SS?

 

[jmangham]

As far as the block, there is no problem going to 383. (blocks are the same) Issues will arise with the transmission. The 4l60e is an electronic transmission and will require feedback from the motor via computers to make it work. best thing is just use you existing transmission. no computers, no problem. I am planning the same motor swap in a 79 MC myself. what i do not know is if the vortec motor is a 4 bolt main or not. if its not, i would consider leaving it a 350. it may not make a difference. someone else will know. other than what you already know and this, should be a bolt in deal.

 

[megaladon6]

the pre LS chevy 350's are all structurally the same. however you may not be able to use a mechanical fuel pump as the late 90's blocks usually had the mount cast over. luckily you can use stock roller lifters on an aftermarket (roller) cam, which is a huge cost savings. but if you get a cam w/over 480 lift you need to have the heads machined--it's easy and cheap.
just as a double check, is the intake a vortec specific intake? the vortec heads have a unique bolt pattern.
the 4l60e will need a 700-4r crossmember, the original TCM, and a Throttle Position Sensor. you will want to reprogram the TCM due to the different weights, gear ratios, and power outputs. you may want to have it get rebuilt with performance parts as the 4l60 wasn't the strongest trans. if it's actually a 4l65e then you're much better off.
unless you plan on running very high RPMs it won't matter if it's a 2-bolt or a 4

 

[a.boddie.matthews]

at the end you say it doesnt matter if its a 2 bolt or 4 bolt, you are talking about as far as a stroker is concerned right..? so, no matter what the number of bolts in the mains, it can be turned to a stroker?

 

[jmangham]

at the end you say it doesnt matter if its a 2 bolt or 4 bolt, you are talking about as far as a stroker is concerned right..? so, no matter what the number of bolts in the mains, it can be turned to a stroker?

yes it can be turned into a stroker either way.

 

[jmangham]

i was wondering about the fuel pump deal also, i figured it probably would be cast over. i wonder if you can have it machined open and make it work, or if it would just be easier to use an electric pump. either way though, no big deal. kind of a chevy noob myself here. been selling parts for about 10 years now, but only really worked on nissans (datsuns) and VWs. figured it was time for a change. worked on my wifes 93 s10 a good bit, but no motor tear downs or swaps or anything like that yet. bringing a 79 monte carlo home soon to start on. i found a good deal on a complete vortec motor and carb intake. trying to sweet talk my wife into letting me get it we'll see how that goes. I am just planning on leaving the motor as is for now with the stock MC transmission ( dont know if it is a 350 or 200 trans gotta get under it and see) and maybe upgrade over time. good luck with yours.

 

[pontiacgp]

at the end you say it doesnt matter if its a 2 bolt or 4 bolt, you are talking about as far as a stroker is concerned right..? so, no matter what the number of bolts in the mains, it can be turned to a stroker?

you can easily change a 2 bolt to a 4 bolt main...you just need to get the 4 bolt caps, drill and tap the block for the extra two bolts and then have it line reamed...

 

[turbo78]

from a machinist's point of veiw, a 2 bolt main is actually stronger than a 4 bolt main block. there is less holes drilled in the casting, making it not as weak in the mains. the only exception would be splayed caps. although the stroking of a vortech 350( which is the platform i run) the money can be better spent on a really good set of heads and the right cam and torque converter. stroking a motor has some bene's, but a well thought out intake ,cam, heads, and ignition system will definately net you both more horsepower and more torque without sacrificing rpm due to a longer stroke. just my opinion and one shared by performance engine builders in my state. bang for the buck is better spent in other ways than stroking a motor.

 

[blk74nova]

I think the fuel pump boss can be opened up at the machine shop. Some blocks were drilled for the mech fuel pump.

What are your goals for the car? Nice cruiser, drag car, little of both? I say build the 383. I have been gathering parts for my 383 vortech. Its easier to change heads later on for more power, than to pull the motor back out to stroke it. My opinion is different than turbo78's. A 350 and a 383 set up with the exact same, the 383 will walk all over the 350 and be a milder motor. If you get the right crank and rods, there might not be any clearanceing needed on the oil pan rails. Get a 1pcs rear main stroker crank( eagle, scat, etc.) and a good set of rods and pistons.

Turbo mentioned sacrificing rpm. You can build any motor to turn whatever rpm you want but durability becomes an issue. If its a race car it may see high rpm for a few seconds during a race. If your car is a street car or a little of both, most of your rpm is around 2000-4500 rpm depending on transmission. I'll take the torque down low where i can use it instead of a bigger hp number at an rpm that isnt used.

 

[Doober]

Keep in mind you'll need a 1-piece rms stroker crank. The only thing not machined far as the pump is concerned is the hole for the pushrod. The pad is still cast there. Also, if you go with a flat tappet cam you will still be using a standard timing set (not for the '96+ roller) and the plastic timing cover interchanges with the older ones.