KZad

In doing a mild modification to my 88 formula's LO3, would it make sense to upgrade to the TPI heads, if I could get them cheap enough (under 100 bucks.) This way I could also send them to the shop to get done (any suggestions?) prior to tearing mine appart.

By mild modification, I mean CAM, INTAKE, AND HEADERS.

Thanks

Kurt

five7kid

iTrader: (14)

Do TPI heads flow better than TBI heads? Without a doubt.

What to do to TPI heads? 1.94" intake valves, porting (bowl work and guide reduction at a minimum), screw-in rocker studs, real valve springs and seals.

Beast5spdGTA

I would go vortec (maybe pro topline version) or really cheap 305 TPI heads (like less than $50 including shipping) and plan on doing your own porting or else I doubt they'll be worth the money.

My 305 TBI is only .1 sec slower than my 305 TPI was with the same mods. I do plan on porting and getting a valve job on my 081 heads then putting them on the TBI later, but that's b/c the heads are free for me and I already have the equipment to port them myself.

I'm hoping to get my 305 TBI into the 13s on the stock LO3 swirl ports.

Aron213

The stock 305 tpi heads have 1.84 valves.

f-crazy

iTrader: (-1)

well fully ported theyll support about 450 horse so it doesnt sounds like a waste to me....vette l98 heads will be closer to 500


that they do and five7 knows this hes saying put a 1.94 valve into them...worth about another 10-15 horse

Beast5spdGTA

But how much does it cost if you were to pay a machine shop to do all the work? I imagine the porting alone will cost a few hundred, plus the normal for a valve job, screw in studs etc. Paying someone else to make the stock heads good will cost almost as much as an aftermarket set of heads. Just a thought.

KZad

So the general decision is to not worry about doing the TPI Heads (that i can get for ~$75), but to get a cheap set of Vortec's for around 500-600. How hard is it to do the work to them anyhow? Just dremel work, or some serious stuff? I think I did a pretty good job doing my throttle body, for example (pic below).

Any other suggestions?

Sitting Bull

Follow the link at the end of my sig. You won't regret it

305sbc

iTrader: (3)

http://www.cardomain.com/member_page...217306&page=22

f-crazy

iTrader: (-1)

not nessasarily beast....if u get the deluxe porting kit from standar abrasives for 120 then do it yourself

Beast5spdGTA

yeah and a $50-80 electric grinder plus ~$10-20 for a speed control, a dremel won't cut it. I agree if you do the porting yourself it could be cost effective, but you're looking at probably 10+ hrs of porting alone, plus the chance of messing the heads up.

I'd say for a mild 305 TBI if the cam is small enough(like a LT1 or L98) find some stock vortec heads used for a few hundred dollars and be done, the vortec carb intakes aren't very expensive. I imagine if you look in junkyards you could pick up a set of vortecs for $200 or so.

I'm not saying porting the 305 TPI heads is a bad idea (I'm probably gonna do it myself), but for a mild 305 you're not gonna have(need) a cam requiring work to be done to the stock vortec heads making them perhaps a better option.

89 Drop Top

While we're on the subject, are certian year tpi heads better than other year ones?

Sitting Bull

Not really.