350 vortex head on a 305

[Longroof79]

It's hardly worth dumping any money into a 305. That's why I yanked the one that was in my car for a 350. I found my 305 ran out of steam out on the open road, besides having little to no torque.

Stick that in your pipe and smoke it...😵

 

[pontiacgp]

It's hardly worth dumping any money into a 305. That's why I yanked the one that was in my car.

agreed, the cost of vortec heads, head gaskets, the intake, intake gaskets and egr set up for the 305 is more then you'd pay for a vortec 350 that you can just drop into place.

 

[Longroof79]

agreed, the cost of vortec heads, head gaskets, the intake, intake gaskets and egr set up for the 305 is more then you'd pay for a vortec 350 that you can just drop into place.

Couldn't have said it any better, Steve.

 

[ssn696]

i have a sbc 305 and i want to put some 350 vortex heads on it whats need to be done to make this a successful process???

I am not positive on this, but before you buy 350 Vortec heads, make sure the valves won't overlap the 305 cylinder bores. I know 2.02 / 1.60 heads have that problem, and I think Vortecs use 1.94 / 1.50 valves. Just ask that question before you drop your hard-earned cash.

Another alternative is World Products' S/R Torquer 305 heads, 58cc chambers, WRL-042650-1, for $550 each. If you look at the cost of Vortecs plus the Vortec intake manifold and fasteners, perhaps these are comparable overall cost since you can reuse your intake and a less expensive stock top-end 305 gasket kit.

I offer advice. I do not require that you follow it.

 

[Clone TIE Pilot]

agreed, the cost of vortec heads, head gaskets, the intake, intake gaskets and egr set up for the 305 is more then you'd pay for a vortec 350 that you can just drop into place.

Unless you are going to reuse the spider injection (which still costs money to wire and pumb up), you would still need a vortec intake manifold of some kind, updated intake gaskets, EGR setup, coolant bypass, etc with a Vortec 350 swap. Plus figuring out how to run a fuel pump since Vortec blocks lack a fuel pump pushrod provision, more expense and troubleshooting. The only thing you would save money on whould be HGs which an electric fuel pump install alone would more than offset. If it is a used Vortec motor you probably still want to pull the intake just to be sure it has the updated design intake gaskets installed. However complete Vortec motors, even used ones usually go for more money than a set of Vortec heads, especially L30 305 Vortec heads since many sell them off cheap because they are 305s which nobody likes 😉. Plus with a engine swap you are going to need a shop crane, $200 at least right there, heads don't need cranes.

Vortec 350s don't just drop it like you oversimplify, they require even more parts than a simple head swap.

 

[ssn696]

I posted this the other day. Is your 305 a 1-piece rear main with the roller cam? If so, you can reuse the crank and rods and just get a blueprinted 350 block from Summit. You'll need pistons, rings, bearings, gaskets, but this is the best thing to do with a 305 if the emission police don't require you to keep the same motor size in your car. As a bonus, the 1-pc. blocks all come with the OEM roller cam provisions. The blocks are drilled for a mechanical fuel pump. As long as there are no flaws in your rotating parts, you should be OK up to about 300 HP.

Just follow this quick assembly video.

 

[Yav8]

Unless you are going to reuse the spider injection (which still costs money to wire and pumb up), you would still need a vortec intake manifold of some kind, updated intake gaskets, EGR setup, coolant bypass, etc with a Vortec 350 swap. Plus figuring out how to run a fuel pump since Vortec blocks lack a fuel pump pushrod provision, more expense and troubleshooting. The only thing you would save money on whould be HGs which an electric fuel pump install alone would more than offset. If it is a used Vortec motor you probably still want to pull the intake just to be sure it has the updated design intake gaskets installed. However complete Vortec motors, even used ones usually go for more money than a set of Vortec heads, especially L30 305 Vortec heads since many sell them off cheap because they are 305s which nobody likes 😉. Plus with a engine swap you are going to need a shop crane, $200 at least right there, heads don't need cranes.

Vortec 350s don't just drop it like you oversimplify, they require even more parts than a simple head swap.

 

[Yav8]

Not sure where your information comes from on the cost of a complete L31 vortec motor. These came in the 96-2001 trucks and vans. You should be able to get one in the yard for under $200 complete with or with out a exchange. Most will clean up very nice and with just a hone and new rings rods mains and cam bearings and a jet wash or lots of scraping scratching and picking in your back yard. You can reuse the roller lifters spider and dog bones for the roller set up and reuse the stock cam or like the article in Car Craft up grade the cam to the 383 or marine cam with the last three numbers being 395. When I do one of these motors with the 395 cam I always add a set of 1.6 roller rockers to match the factorys 350 ram jet specks. 350HP and 400 TQ, I have the same motor in my fun truck with weights 4425lb and runs 14.50 in the quarter mile at the local track. Take 1000lbs off something like a gbody or a S10 and its a easy low 13 second ride. Not much is needed just a intake carb and a HEI and a inline electric fuel pump some where back by the fuel tank. I have done well over 300 of these vortec motors and it always impresses me how much power these motor make for very little money. One other thing you can do is with drop in a stroker kit and make it a standard bore 377 or bore it and be happy with a 383. Add a matching hyd. roller cam a up grade the valve spring and your around 450-500HP for not a lot of money. If some one has question just drop a line and I will help. I am retired and do these as a hobby, just to have something to do in the evenings at the shop.

 

[ssn696]

http://www.summitracing.com/parts/nal-14097395
The nice feature on this cam is that its max lift is .451 which is below the max recommended lift for OEM Vortec heads, which is .465. No machining required, even with 1.6 rocker arms.
For a timing kit, use:
http://www.summitracing.com/parts/nal-12371043
I built a 350 for my wagon with this combination. Alas, it's parked right now until I get my weekends back...

 

[ssn696]

When I do one of these motors with the 395 cam I always add a set of 1.6 roller rockers to match the factorys 350 ram jet specks. 350HP and 400 TQ, I have the same motor in my fun truck with weights 4425lb and runs 14.50 in the quarter mile at the local track.

To hit these numbers, what do you use for an intake and carburetor? What rods/jets do you use for the carb?