ok i am planning out my motor swap. i am going from the 305 tpi to a 350 that i will build myself. i plan on using a junkyard 350 and start from there. any type of block i should look for? 4 bolt mains i know are preferable, but not a necessity since the motor will not be extremely modded. but as for the heads, what heads should i use? i am trying to plan all this out early, and i was considering sportsman ii's, although i'm not sure if everything will bolt up correctly especially with the tpi system.(i plan on keeping the tpi). on to the next, what parts/steps will i need to be sure to use/do that you guys can think of off hand? i'm trying to really get this show on the road and i know planning is essential. also what kind of cam do you guys use without having to burn a new prom? i want very reliable and streetable with some power gains over stock.

finally, i just want to finish up by saying i'm glad everyone is willing to help eachother out with PITA questions like this. i want this motor to make somewhere around the 360-400 ft. lbs. of torque and around 350 hp. any comments or answers are greatly appreciated. am i on the right track? (first time motor builder, young, slightly foolish):lala:

 

The Sportsman II's will want more than TPI-like RPMs. Torquers are available in '87-later style, but only with the larger chambers. You should be able to modify your base to fit the center two bolts to the 67cc chamber Torquers, though (they will take the center bolt valve covers).

You should plan on shorter runners, as the stock ones will kill most any upgrade cam. Then, get a computer-compatible cam from Comp or Crane.

I assume you're planning on a headers, if not a complete new exhaust.

Optional are 52mm TB, 22 lb injectors. PROM work will probably help.

 

i didn't think of the low rpm range of tpi, torquers are the way to go? can you hook me up with a company name? maybe a website? i want to keep the cost down so i want to get some used maybe, not sure yet, budget is tight

 

http://www.worldcastings.com/sitemap.shtml

 

Another alternative is to use the heads that are on your 305TPI
now. These should be "081" castings. These head castings
have good performance potential if/ when ported.
If you were to port them and have them reconditioned with 1.94 x1.60" valves along with the proper valvetrain for your new cam plans, they will work quite nicely.
They have the advantage that they fit and you already have them.

 

how much does a port job cost roughly? i dunno about valvetrains much besides the general idea on how they work. i just want to keep it simple and affordable.

 

www.competitionproducts.com had the best prices for the World heads when I bought mine last year.

If you use the 305 heads, you will want to use dished pistons in the 350, because the 58cc chambers will raise compression too high with flat tops. If you aren't willing to do the porting on the heads yourself, you're looking at a couple of hundred there (somebody will say, "I got it done for $75." Right, in 1977, perhaps). 1.94" intake valves another $150 or better (valves and labor). Plus the normal rebuild, usually a couple hundred, plus you'll want to replace the press-in rocker studs with screw-in type (probably about $75 parts & labor). And new valve springs to match whatever cam you get. You're almost up to the price of the new heads that already have all those goodies.

Since you have an '88, you'll also have self aligning rockers. If you reuse them, you'll want to drill out the pushrod holes in the World heads (no problem if you go with the 305 heads). If you get new rockers, don't drill out the holes and the get non-self aligning type (again only if you get the World heads - new rockers with the 305 heads will have to be self-aligning).