I may have a TPI off of a 350 on the way soon, and was wondering if it was even worth it to mess with the 305 on my RS, bore it out, and build it up. If so, what heads would I need to retain compression, and would 22lb. injectors be too much? I can get a pretty good built-up 350 for 1600 bucks (The guy's exact words were "It'll hunt!"). I'm wondering which route would be more cost effective. I was wondering if any of you guys haved bored out a 305 and how much it cost to build it up. Thanks guys.

James

 

If you have the opportunity to get the 350, then building the 305 isn't worth it. I believe that with the maximum allowable bore without hitting the water jackets, you can bore it to a 315. Still only worth less than 10hp, though. Though it would be pretty cool to see someone build a real stout 305 TPI (Preston Smith and Willie come to mind), for those of us like myself who are on a budget, the 350 is just more economical, yielding more HP per dollar.

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91 Trans Am WS6
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

supposed 'peanut cammed' car (yeah, right)

MoreMoodThatMod

 

It costs exactly as much to build a 305 as it does a 350 ($1500 or thereabouts) if not more. IMHO it is stupid to pour that much money into a small motor, when you can get a 350 core for $200. You'll have to go through all the usual rebuild steps with your 305: cleaning it up, boring it, honing it, and painting it; then buying pistons, main & rod bearings, cam bearings, oil pump, a cam, lifters, timing chain, and gaskets; then pay someone trustworthy to assemble it. All that costs the same as a 350. Why spend all that money and leave out 45 cubic inches that you can't put back in later?

The best heads you could conveniently get would be a set from an L98 (TPI 350). They're not the greatest thing in the world but they're fairly easy to come by, in fact you might want to check the classifieds on this site.

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"So many Mustangs, so little time..."

 

In your case it would probably be better to get a L98. The 305 tpi is a good engine (I have one) but it would cost so much to change your engine over to tpi, why not just get a bigger one while you are at it. If you are looking for something "different", I have seen a few people stroke the 305 to a 327. I hear that engine really screams. Just something to think about.

 

I did a top-end rebuild of my 305 this year, and now turn about 98 MPH in the quarter mile with it. If I would have had to go into the shortblock, I would have paid another $100 and bought a used 350 shortblock.

If your 305 shortblock is in good shape, go ahead and build it up as a top-end rebuild. If your 305 needs rings & rebore, and you are after the best performance-per-dollar, just let it go. Cost-per-HP is cheaper in the 350 platform. A 350HP 350 is going to idle well with off-the-line snap. A 350 HP 305 is going to snort and snarl, with low vacuum and little low-end torque. It'll also require you to rev higher which is harder on parts.

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Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines,
5-point racing harness, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Speed-sensitive steering conversion, underdrive pulleys, Crane Hi-6 & more. 1.05g skidpad verified.
New best E/T! 14.400 at 98.6 MPH in 88 degree air at Stanton, Michigan.

 

If I understood your post correctly you have the 350 injectors on the way. Unless you are planning major mods for the 305 the injectors may be slightly big for the application and rather expensive to replace. In this case I would go for the 350 since that is what the system came from and I assume the computer is from the same system so the prom will be more compatible with the larger engine.

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"84Z28/'91 305TPI comp cam flowmaster TB coolant bypass/shutoff valve to heater core MAT relocated Ram-Air(home-made) gutted air-box IROC ground effects/wheels GY245/50's 700R4 superior shift kit/ corvette servo(excellent shift kit BTW) Rebuilt engine and transplanted it myself. Love this engine!
LOW performance people should drive low performance vehicles!

 

I whole-heartly agree with Daniel Burk (ws6transam) on this.

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George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

 

A cam,full exhaust,bigger injectors,gears,and a super charger would probably get you into the mid 13s.

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We need Perry Mason

 

I think so, but I am bias to this because it has been my plan for along time. I had the famous self debate of weather to get the 305 TPI 5 speed or the 350 auto. When it came down to it, I realized I really love shifting and the e/t's ussually were lower with the 5 speed. The problem comes when you hear advertised power gains for V8 camaros. Every single part you buy for your 305 is going give you less horsepower than the same part would on the 350. This is an obvious given. This doesnt mean in anyway good(fast) things aren't possible. This, soley is my inspiration to make a high 12's all motor 305. This right here=> I was at the track when I saw a black neon with full interior run a 13.6 on ALL MOTOR. This is a freaking 4 cyl that has been completely rebuilt. It was not turbo, no sc, not spraying. Granted, that had a huge amount of work done, but it just shows with half the displacement you can get a really good E/T. I my self am a full second slower than that neon but I have only bolt ons. Now that I've gone way off topic to try and answer a simple question, I will reinstate waht was previously said. Yes, yes I do. I think it is worth it. Weather you do it to be the underdog or just out of boredom, i think it's worth it alone to be something diferent. good luck!

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-Red '88 IROC 5 Speed TPI
-Dual Friction Centerforce Clutch
-Accel 300+ Racing Ignition
-Accel 300+ Pro Sleeve Plug Wires
-Accel U-Grove Plugs
-Flowmaster Force II 3 Chamber Cat Back Exhaust
-Hypertech Chip
-Hypertech Airfoil
-Removed MAF Screens
-Gutted Air Box
-Best E/T 14.90(bald tires, SES light on)
-Best MPH 92.4(bald tires)

 

if your going with an engine bigger than a 305 why not get a 400 instead of a 350? If your keeping the 305 and building it up that would be cool to.......... mildly port your stock heads, headers, pulleys, crane cam, and make your own intake with a K&N cone filter and PVC piping for some budget performance under 500 bucks, all this could get you into the 13's if your running mid 14's now, then before you spend alot of money on aftermarket heads, gears, forced induction, decide if your happy and want to take it further.