Need help w/ a few things! ūüôŹ TBI conversion to Carb.

Wageslave

Royal Smart Person
Jan 25, 2017
1,444
113
On the 1st point, yes you will likely lose lockup through the ECU, but you can get kits to replace the automatic functionality. Until you replace the 2.29 gear set, you may be better off just leaving it disabled for now.

On the second point, I used the stock pushrods for a Vortec headed 350 in my setup. When you do change heads, make sure to get the correct rockers as they are different than non-vortec heads. Also try not to overtighten the intake bolts as they will cause vacuum leaks that can be hard to troubleshoot.
 
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Wageslave

Royal Smart Person
Jan 25, 2017
1,444
113
I will also add that if you want to get Vortec heads on the cheap, Autozone is a good way to go. You will need core return heads, but I got my set for $600+ tax and it came with the correct rocker set.
 

MonteLS_84

Not-quite-so-new-guy
Thread starter
Jul 28, 2021
28
3
I will also add that if you want to get Vortec heads on the cheap, Autozone is a good way to go. You will need core return heads, but I got my set for $600+ tax and it came with the correct rocker set.
Good to know! I'm still trying to figure out why some people are running vortec (7.2") pushrods, and others (like yourself) are running the traditional 7.8". ūü§Ē Does that have to do with the lift of the cam?

By the way, what cam are you running with the vortecs?
 

Wageslave

Royal Smart Person
Jan 25, 2017
1,444
113
Good to know! I'm still trying to figure out why some people are running vortec (7.2") pushrods, and others (like yourself) are running the traditional 7.8". ūü§Ē Does that have to do with the lift of the cam?

By the way, what cam are you running with the vortecs?
I'm not totally sure on the push rod length thing, but I think the Vortec push rods are used on roller cam engines and the traditional flat tappet lifters use the longer push rods.

I am housing a Comp Cam's XE262h cam. A lot of people go with the XE268h but I was worried about coil bind with factory springs and didn't have the tool to cut the spring seats at the time.

You can also get beehive valve springs to get around this problem, but my motor was built with 0-5000 rpm performance in mind and the factory springs are good to 5500 rpm so I couldn't justify the cost of the beehive springs to let me use a slightly larger cam
 
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Scoot-71

Apprentice
Nov 13, 2018
91
33
Rio WI
I would just make this engine totally non computerized, stuff an edelbrock 600cfm and an aftermarket hei distributor in it, the trans needs to be identified, if it is a 350c who cares if the torque converter locks up or not, 2 reasons for a lock up converter, better mpg and with an o/d trans it locks up due to low cruising rpm would leave it always in the stall range there by overheating the fluid. You cannot get a computer carb to work correctly without the matching wiring and ecm, all a basic engine needs is one vacuum line to distributor, one to brake booster and one to your hvac system. If it was a truck tbi its not a roller cam engine. I think it was 86 or 87 gm went to center bolt valve covers, those will have the straight up and down center intake bolts, we used to slot the holes and grind the angle so the bolt would set straight. If you are getting different heads get the 64cc chamber itll bump compression up a point, But if its only a 305 you are screwed on getting cheap compression unless you get 58cc heads and angle mill them. Just my 2 cents
 
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MonteLS_84

Not-quite-so-new-guy
Thread starter
Jul 28, 2021
28
3
I would just make this engine totally non computerized, stuff an edelbrock 600cfm and an aftermarket hei distributor in it, the trans needs to be identified, if it is a 350c who cares if the torque converter locks up or not, 2 reasons for a lock up converter, better mpg and with an o/d trans it locks up due to low cruising rpm would leave it always in the stall range there by overheating the fluid. You cannot get a computer carb to work correctly without the matching wiring and ecm, all a basic engine needs is one vacuum line to distributor, one to brake booster and one to your hvac system. If it was a truck tbi its not a roller cam engine. I think it was 86 or 87 gm went to center bolt valve covers, those will have the straight up and down center intake bolts, we used to slot the holes and grind the angle so the bolt would set straight. If you are getting different heads get the 64cc chamber itll bump compression up a point, But if its only a 305 you are screwed on getting cheap compression unless you get 58cc heads and angle mill them. Just my 2 cents
I decided to say screw the vortec and ordered some aluminum heads with 200cc intake, 64cc combustion. 2.02, 1.60. I also ordered msd distributor, and edelbrock 600 carb., with rpm air gap intake.

Talked to a local trans. shop, and they are going to throw in my 3.73 posi, and do the trans. Seemed kind of pricey.. but he assured me the trans. would be more than what I need. I'll post what he told me in the next comment..
 

MonteLS_84

Not-quite-so-new-guy
Thread starter
Jul 28, 2021
28
3
Screenshot_20210830-182916_Messenger.jpg
 

Scoot-71

Apprentice
Nov 13, 2018
91
33
Rio WI
I decided to say screw the vortec and ordered some aluminum heads with 200cc intake, 64cc combustion. 2.02, 1.60. I also ordered msd distributor, and edelbrock 600 carb., with rpm air gap intake.

Talked to a local trans. shop, and they are going to throw in my 3.73 posi, and do the trans. Seemed kind of pricey.. but he assured me the trans. would be more than what I need. I'll post what he told me in the next comment..
200cc is kinda big for a mild engine 180 - 190cc will give you better lower end drivability but does give you room to grow
 

MonteLS_84

Not-quite-so-new-guy
Thread starter
Jul 28, 2021
28
3
200cc is kinda big for a mild engine 180 - 190cc will give you better lower end drivability but does give you room to grow
Man...that's a real bummer. My mechanic buddy told me to get the best flowing heads I could find...and I took that literally.

I did some reading, and you're right. I'm seeing mixed reviews. Some say they're running great with a similar set-up, other say a little sluggish at lower RPM. I guess I'm wondering what is meant by sluggish. It'll be as sluggish as it is now? Or sluggish in for a built up motor? I mean, if it performs significantly better than now, I guess I'll be happy for a while.

I'm going to call comp and see what cam they recommend. It would be a lot more practical to get another cam, rather than send the heads back...if I can use them.
 

MonteLS_84

Not-quite-so-new-guy
Thread starter
Jul 28, 2021
28
3
Does anyone know (Google didn't help)...

I bought a used eddy performer intake...it has a crankcase breather installed. I also ordered new (pricey) valve covers. They have breathers as well. Will running "both" intake and valve cover breathers have any negative impact?
 
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