1993 5.7 TBI to carb in a '69 questions....

[ChevLoRay]

I have a '69 that is apart....completely. My son-in-law has a '93 4WD with a bad transmission. It looks like he's gonna part it out. Before you jump to conclusions, I gotta tell you the truck looks like he drives by ear and is deaf. The left side is still on the truck, but I don't know how.

Anyway, I was just wondering if the engine in it would be decent if converted to run a carburetor, in my '69?

I know that there are a few people here who have carbureted their engines in their OBDI vehicles. So, I'm hoping one of them will tell me what I need to do to make it happen, successfully.

[bloertcher]

Its more than feasable,I know the performance products intakes are already set up for the bolt angle on the center bolt hole angle on the intake.Just don't expect it to be a powerhouse,with a good intake,4 barrel carb and headers,it will be a LITTLE better than stock TBI form.

[dukcaln]

is that all that needs to be done to convert it to carb

[scotts62]

Yep intake and new carb and roll, I think you would be happy with it and it will run pretty good.

[dukcaln]

reason why I asked was that my father in law bought a really nice 87 tbi motor and trans. It was really chromed out and the tranny has been rebuilt. He wqas having issues with it staying running. Would run on with throttle but just would not idle and still won't. so I think he was considering to convert it to a carb... I know he really likes the idea of the tbi power and the tbi fuel milage vs carb, so i guess it depends on cost and if we can figure out the non idle issue. Nice to know it is a pretty simple conversion. Thanks for the info

[ChevLoRay]

Thanks, Scott. I don't know if I can get the engine, or not. I know that my son-in-law can probably sell it and if it comes to me, it'll probably be low-cost.

I drove an '00 Z-71 today, to check it out for my daughter and him. It's got 180K on it, and the leather is a little weak, but ride and drive were really good. This truck would be to replace the '93 Z-71, which has a bad transmission and really would be worth more than the rest of the truck. He really needs to learn how to drive, when he's off-road. The ADD/ADHD factor is the death of whatever he's driving...well, not when he's driving, but when he's finished driving. I've learned to stop, put it in park, set the brake and THEN you can get out of the truck. He's still learning. Trees and stuff are not too kind....neither is rolling backwards and finding a resting place.

But, my reason for asking is because I was wondering if it wouldn't be a better choice in the long run. Is the '93 a roller block and does it have a one-piece rear crank seal? Would I be able to use my flywheel/flexplate or an aftermarket one? It has an automatic, as does my '69.

[Warrens69GMC]

To install the 93 into the 69 -

You need-
carb
intake (they made carb intakes for these years, check sub and blazers)
distributor
Electric fuel pump (if no fuel pump lobe)
flexplate (maybe)


I can't rember if the 1993-1995 flexplate has the same bolt pattern for the torque converter as a T350/T400.

Your 93 block will have roller provisions and 1pc seal - you need the cam/lifters/holddown to take advantage of that. Look for a L31 vortec (96-2000) complete assembly.

[Boog]

Don that'll make a good swap for your truck. It's what I did with mine. I bought an 88 tbi engine. Had it bored and cleaned up. Bought an Edel Performer intake and headers for it from Jegs. RV cam. I am about to put in a skip white dist and new wires. I of course used a Qjet too. It's a great combo.
If you have a good shortblock to start with pickup some vortec heads. They are said to be some of the best addons for small blocks.
I used a regular flexplate for a 350 and bolted up the T350 tranny. Some late 80s to early 90s engines still had the fuel pump hole in the block. Mine did so a mech fuel pump bolted right up. I still haven't had mine on the road but it sounds good.

[scotts62]

Most are roller blocks but not all are roller cams and lifters so check that out too. If it is drilled for the fuel pump boss but the cam does not have a lobe you can just change cams. They run good when they are converted.

[ChevLoRay]

Thanks, guys!

[peglegs]

Boog, i just got a rebuilt 87 350 tbi truck long block for a good price and thought about the vortecs, can i use my 87 head bolts? is there also a carbureted manifold for the vortec heads besides aftermarket.

Another thought was using my 67 327 heads & manifold on the 87 if so you think they would they be a bolt on? thanks for the info i was really concerned if i bought the right motor & feel better reading this post.

[Boog]

Pegleg is this engine for your 67? If so your 327 heads and manifold will bolt right up. If that long block is fresh or low miles I'd want to use the heads on it but that would require modding your stock manifold just a bit. The two center manifold bolts on a TBI engine stand straight up rather than at an angle like the rest of the bolts. You only need to take a grinder to slot those manifold holes to make it work or buy an Edelbrock manifold as I did.
I hear guys say never reuse head bolts. FWIW I've rebuilt a number of engines over the years and have always reused them and never had one fail.

[peglegs]

Originally Posted by Boog

Pegleg is this engine for your 67? If so your 327 heads and manifold will bolt right up. If that long block is fresh or low miles I'd want to use the heads on it but that would require modding your stock manifold just a bit. The two center manifold bolts on a TBI engine stand straight up rather than at an angle like the rest of the bolts. You only need to take a grinder to slot those manifold holes to make it work or buy an Edelbrock manifold as I did.
I hear guys say never reuse head bolts. FWIW I've rebuilt a number of engines over the years and have always reused them and never had one fail.

thanks for the reply boog

Yes it is going to replace my knocking main bearing 327 in the 67

i rolled the 87 over on the stand and the lifters do appear to be reg. hydraulic not rollers i wouldl like a roller cam and may bump it up from stock a bit.

And my heads will bolt up therefor the manifolds will .......if i want to use just my edelbrock manifold on the 87 long block i will have to work on the center manifold holes?

another question, on the 67 i have fuel inj./ power pack heads (skinny pyramid on a rectangle head end casting) 9.25:1 CR, 1.72/150 valves would this valve lift be compatable with on the 87 block piston/valve clearance? The 87 heads have a 1.84/1.50 but dont know the CR.

Are these 2 heads close that their may not be a gain?

i dont know that much about all this any info is greatly appreciated, thanks again for your help man.

[Warrens69GMC]

What heads (casting)are the 87 TBI heads. All of the 350 heads had 1.94/1.5 valves, and the 305 had 1.84/1.5 valves. Does you block have the 3 "risers" in the lifter valley for a roller cam?

[peglegs]

Originally Posted by Warrens69GMC

What heads (casting)are the 87 TBI heads. All of the 350 heads had 1.94/1.5 valves, and the 305 had 1.84/1.5 valves. Does you block have the 3 "risers" in the lifter valley for a roller cam?

casting #'s 14102193. http://www.chevymania.com/ came up 350/305. This engine came from a now closed rebuilder around San Francisco it has a revited on tag, sounds like 305 heads huh, so i might be better of switching over my 327 heads?

the enclosed pic is the 87 350 valley are these the "3 risers" thanks for your help.
The block also has a bolted fuel pump block off plate so if i can install a roller cam it has to have a fuel pump bumper.

[Warrens69GMC]

193's have the 1.94/1.5 valves


Interesting, it should have three risers

[peglegs]

hell my 3 is different than your 3 lol, guess no roller cam huh would i benifit that much by using the 327 heads?

[capev86]

convert to full roller valve train while you have it apart. reduced friction=less wear and less power wasted. and the you get cleaner oil and less top end noise.

if i ever take the 307 apart in my 72 Burb C20 (which runs great), it will get a 400 crank stoker kit and an RV grind roller top end.

also, if you have all the parts from the donor, keep the TBI setup for better mpg and the ability to adjust to altitude changes. you could bore out the small block intake and use the TBI unit from an early 90's big block truck for 700cfm of flow!

only carb that works for me is the tried and true Rochester Quadra-jets used by GM. good low end, economy AND wide open power. pulled the original 2 barrel, installed an edelbrock performer intake that takes the spread bore carbs and put a q-jet on. best ones are full mechanical units from 77+. http://www.cliffshighperformance.com/parts.html can take 'em from great to bulletproof.

[peglegs]

wow i was hoping to get this settled but sorry to say im no further ahead now than when i posted.....does anyone know for sure if i can use a roller cam i also posted in another forum and didnt get any answers but guys go on & on about the most minute carb detail for pages & pages but i guy looking for info for a daily ride decision gets nada.......im really disappointed i would like someone with knowledge to say YES you can instead i now have more doubt , sorry

[Warrens69GMC]

You would need a retro roller setup to use in that block. You don't have the three risers for the hold down and look at the area above the lifter bores in my photo, your block does not have the extra pad area to support the factory dogbone hold down.

[Warrens69GMC]

here you go,
http://medford.craigslist.org/pts/2530596731.html