91 RS 305 TBI to 97 Vortec Chevy Truck 1500

So Ive been thinking about this swap. I met a guy from around here who owns a shop that rebuilds engines and does swaps and what not. Anyway he wants to sell me a fully rebuilt Vortec 350 engine from 97 Chevy Truck 1500.

Hes asking for 900 dollars for the engine and 500 for the install fee. + he was telling me to go carburetor instead of fuel injected because according to him it was not only cheaper but got the most power out of the engine.

I have a few questions concerning this swap though.

-Would my 700r4 be compatible with the engine swap?

-What else would i have to change to go straight to full out carburetor instead of TBI?

-What horsepower gains are we talking about here with the swap?

-Would it be worth it, or a waste of my time?

-Where can i find the casting numbers on the chevy truck engine?

-What questions should i ask before i decide on buying?

-Any conflicts i should be aware of with this swap?

I plan on carefully planning this out before i even make a move on this swap and could really use some opinions on what i should and should not do.

Total with parts (intake and all that) he estimates about 1800$ for it all.
The guy encourages me to just wait and save up about another 400 dollars and put in some good lifters and cam ( only have about 1850 atm), and he would do it for free since the motor would still be out.

The shop looks pretty legit and all, i always go and see rebuilt engines painted and what not, and the guy himself drives a nice suped up Mach 1. I would say i trust this shop about 70% but u know its always good to be skeptical.

Since i got my thirdgen all i wanted was for it to run good and be able to produce decent power, not too much but enough to not get smoked by civics and camrys or galants..(yes ive had my share of embarrassments) My car has never been in top shape since i bought it a few months ago and Tbh its been quite a ride. This car has taught me so much so far and gave me tons of learning experience. I knew what i was getting into when i bought the car and cant wait for it to one day be good as new, even though it will take me some work im willing to put the effort in i just need a push into the right direction.


Thanks for reading.

 

Engine itself is a straight swap, everything in your car now bolts up except the intake manifold.
Do you get to keep your old engine to sell?
Vortec truck engines are 300 / 330Hp ?( with factory TBI )

All SBC have block casting # in same place.on bellhousing area behind drv side head

 

yes i do get to keep my engine. I also thought i would use my old 305 engine to experiment on, opening it up and replacing internals, maybe even use it as a back up engine in case anything happens.


So it is a straight forward bolt on? i think he mentioned id have to use the oil pan on my 305.

Thanks for the casting # help im gona check that out

 

More important than the block casting #, is the HEADS one(s).

"Vortec" is not a property of the block. It's THE HEADS. If it doesn't have Vortec heads, it's not a Vortec motor, even if the block came out of a 97 truck as part of a "Vortec" motor.

The ONLY casting #s for Vortec heads are 906 and 062. Any other #s, and they're NOT Vortec; and if not, you don't really want that motor.

I'd suggest placing an eyeball on THE motor he plans on putting in your car and making sure that's what it is. It's all too common these days for people to end up with TBI heads :barf: after somebody told them they were "early Vortec", "Vortec like", "Vortec prototypes", "just like Vortec", "as good as Vortec", or even my absolute all-time fave way to slide the buzzword in without really saying anything, "pre-Vortec" (which of course covers ALL 95-back heads).

You will HAVE TO have another intake if thy're Vortec heads, regardless. The one that came in the truck (the CPFI setup, with the "spider" thing) won't work in your car, and your intake won't fit those heads. The engine should have the roller setup in it; an excellent cam for a nice daily-driver type application with some pep, is the ZZ4 cam, which you can find on eBay and elsewhere, brand-new, that somebody is taking out of a new ZZ4 and putting something else in, for dirt cheeeep.

I'd suggest getting a good 4-bbl intake and a TBI adapter. The ONLY TBI intake for Vortec heads, the one you can get from Edelbrock or from GMPP, is not highly thought of. If you go the adapter route, I'd suggest a Performer RPM; and make sure whatever TB adapter you get puts the TB back in the stock place. One of them, I think it's the Holley one, DOES NOT; and that makes fitting everything back on there (throttle cable and fuel lines) almost impossible. Not sure what they were thinking when they did that but obviously whoever designed it wasn't required to install it on his own car.

You'll need bigger injectors and a 350 chip (get those out of a TBI truck or Caprice), and a 350 knock sensor (should already be in the motor but who knows). One of those injector pod spacers might be a good idea as well, and make the fuel pressure reg adjustable.

 

most likely need different serpentine brackets, my donor motor came out of a 96 tahoe. After research and acouple thread posting i've been told numerous times the brackets sit too high on the motor to clear the hood. Just a FYI. You can use your setup on the 305 though so no biggie.

If you have the 305 now, which i think you do it will be a huge power upgrade for you, like other said the vortec motors are rated between 300-330 hp. The 305 are what? 190hp?

would agree with your engine guy, do a cam swap now seeing the motors out, headers, 3 inch exhaust and i think you will be very pleased with it. Vortecs dont like lifts bigger then .500 so be carefull on the cam selection, unless you want to upgrade the heads also.

The 700r4 will bolt up to it, but its going to be very stressed with the vortec power. They struggle with the 305 power. Few upgradeds on the 700r4 and you should be ok.You have the stronger of the 2 10 bolt rears, i think it should be fine under a "almost stock" vortec.

I think a cammed vortec should be good for a 13 second pass, i had a grand prix gxp stock pushing 248whp that hit 13.7 @ 102. I could see a cam vortec push alittle higher whp then that. Sounds like a deal if you can verify the heads on the motor are true vortecs

 

Quick check.
Vortec heads have only 4 bolts holding the intake on ; not six like reg SBC heads.The bolts are at a different angle also

 

your gonna have money in an intake,carb,and distributor...dont put the factory 305 manifolds on that engine.. use headers... and unless your good with carbs.. make sure he throws in tuning it.. good luck

 

with headers, 600 holley 4160, 700r4, peg leg 3.42, on an otherwise stock 97 vortec 5.7, I ran a best of 9.28 in the 1/8.

 

Carb on a 91.....Can't legally do that for a street car. That would be against the Federal Emission Laws.

Plus your MP/g would DROP. You wanna drive it without stopping at gas stations more often? Stay TBI In fact, for the "best" with that swap....Put the Vortec engines ECM in too & you'll really have something there. Costs more to adapt that ECM & wiring in, but you gotta pay to play!

 

I agree! If I could reverse time I would keep my car FI. Previous owner threw the carb on my car, but one day when the money is right, she is going FI.

Since you have a perfect start with what you have already, I would keep it FI and not just for legal issues, mpg, cold starts, etc.