Ok let me say first i SEARCHED... But search suck.. I have a305 TPI in my car right now. It's pretty much about to die. I have a 350 that has a rebuilt bottom end with pretty good parts, and stock heads. It came out of a 1985 blazer, originally had a holly carburator and stuff... Well i decided to put that 350 in my camaro.


Here are some of my questions. Should i rebuild my 305 heads and put those on the 350 so my tpi will bolt up easier?

What computer probloms will i have with this swap and what can i do to it.

I think thats about it for now.. Thanx for any help....


Eric


EDIT: Will there be anhy problems with the cam in the 350. Some just told me ill need to run a different cam with my fuel injection. It currently has a mild cam in it..

 

I wouldn't use the 305 heads because they will most likely have smaller intake runners and smaller valves. Only difference you might have with the heads bolting up is a different angle on the intake bolts. Unfortunatley, going from a new (1-piece rear main) block to the old style (2-piece rear main) will probably require you to get a different flex-plate/flywheel and different starter.
As far as the cam goes, I would get a TPI friendly cam.... there is no telling how 'computer friendly' that carb cam is going to be. It might run lean with the stock 305 injectors, but a lot of people replace those with LT1 injectors, they're cheap to buy used or SLP sells 25/lb. injectors for $99/set.

 

Smaller valves, yes (although the Blazer engine may have small valves as well). Smaller runners, no.

But "yes" on smaller chambers, which wasn't mentioned.

Most likely the '85 engine has dished pistons and large chamber/poor ports heads. The 305 heads with 1.94" intake valves installed would be a very good idea, most likely.

For cam, get a flat-tappet TPI type cam. Talk to Crane or Comp (or any of the bigger outfits). Stay away from off-the-shelf $59 cams like Summit or Elgin brands (amoung others).

You'll need some of the typical 305->350 TPI parts like knock sensor. The injectors will be fine for the most part, but might get lean at higher RPMs/demands. And adjustable fuel pressure regulator can help there, but 22 lb injectors are fine for a basically stock 350 TPI. Any more with a mildly-built engine and you'll hurt yourself on low end performance and fuel economy.

 

I second refurbishing your 305 TPI heads for the new 350.
the only difference between the 305tpi (081) and 350TPI (083) [L-98] heads is the combustion chamber size and intake valve size. rebuild them with new 350size 1.94-1.60" valves. Fitting these larger valves in your heads will result in a little chamber volume increase. [60-63cc+/- (unshrouding).

Now give them a good porting and throw them on.
they'll work great. Pick a cam with moderate/short duration and wide 112-114 LSA for a TPI motor.

A Crane Powermax 278-2 is as big as i'd go for TPI.
Small is probabily better overall.
www.cranecams.com
Part Number: 113931 Grind Number: H-262-2 (REPLACES H-266-2) looks good to me.

 

Shouldn't he currently have the 19# injectors with the 305? Stock for the 350s were the 22#.


FYI Comp Cams recommended the XE262 flat tappet cam when I swapped my 305 to a 350, but I went with the XE268 anyway.
http://www.compcams.com/Technical/Cu...ML/128-169.asp