Vortec heads on TBI engine

[fslay]

I was wondering if anybody here has ever used Vortec cylinder heads on a TBI engine?  If I am correct, this requires use of a Vortec-specific intake manifold.  So I have a 1987 1/2 ton with a 305 TBI and TH-400 tranny, and 2.73 gears.  If I went with Vortec heads, Edelbrock TBI intake, aftermarket throttle body (Holley, Turbo City, etc), a good cam, headers and about a 3.55 or so gear, what difference could I see?  Also, my understanding is that a TH-700R4 has better gear ratios that would be better suited for taking off under acceleration than the TH-400, what difference would the 700-R4 make?  Also, any suggestions on specific part numbers (cams that work well, etc) are much appreciated.  Finally, are there any differences in the Vortec 305 heads and Vortec 350 heads (i.e. valve sizes, etc.).  Thanks so much  

[Sano]

I have personally never bought any vortec heads or anything but yes you do need the vortec style manifold. Suprisingly if you do have a 305ci engine then you have to be careful on how big of a cam you put in as well as the heads you swap on it. If i remember correctly the heads on a tock 305 are very restricted by small valves/ports/chambers and what not. I know if you got a vortec head which are normally made for the larger ci sbc then it would drop your compression ratio unless you shaved the head down or a number of other things. The gears will help a lot but your gas mileage suffers along with a mild cam. I think but I'm not sure, when you change a cam in a TBI motor that you have to change some cpu codes for fuel delivery and such. As for transmissions, unless you build up a 700-r4 then the T400 is much better. The 700r4's weren't all that tolerable to powerful engines, the later model 700r4's(88 and up) are a little better. I think comp would be the best bet on cams, you can even call them up and ask them what would be the best cam for you and what you might need to do. Have any more questions ask, there are tons of ppl on this board that can help

[TRUCK6DRIVER]

The Vortec heads will fit on the block but as of this date the do not make an intake for TBI on them. You can get a 4bbl intake to fit the heads then buy an adapter plate from painless wiring to put the TBI on the carb intake. As SANO stated the 305 heads were 58cc and 64 cc heads with 1.80/1.50 valves. The SR torquer 305 heads may be a better choice for your application. They are 1.90/1.60 valves and still have the 58cc chambers. They were designed to work with the 305 and are cheaper than the Vortec heads. You can run Crane's compucam cam shafts with the computer systems. I ran a Compucam 2040 in my Monte Carlo with great results. They have 3 different cams for the 305.
2030 which is a Z-28 replacement cam
2040 which is good with mild street applications
2050 which requires a tall gearing and recommends a stick or stall converter.

A 305 will make decent power if done correctly. Big cam, heads and carb will not work on the small bore-small blocks. It will hurt performance. Concentrate on better flowing exhaust, ignition, gearing, and an injector upgrade to a 350 injector for the TBI.
Ray

[lotopp79]

tbi vortec intake pace has them and there is a vortec 305 head I cant remember the number but its awsome for the 305 they brought a junk yard motor from a tired 16o hp to a engine smoking 210 before chaning the cam to a 268 xe i think and finishing off the motor in a old sport truck artical I have some where around here