I have a 305 TPI engine w/ a 5 spd manual. I know everyone thinks this is crazy but I want to build up the engine that I have. I'd like to do a new cam and head combination but I'm not sure where to start. I'm going to be pulling the engine this winter and bringing the block to a local machine shop to be refreshed. I'm looking for mild upgrade suggestions. I wouldn't be opposed to installing new pistons either, I'm just not sure what combinations work together. My stock intake manifold and runners are match ported and I do have headers on it already. My goal is to be able to drive this under normal driving conditions and give it hell too. I know the best of both worlds doesn't always work but it's what I'm going for.

 

I would recommend a Lunati 60102 for a Cam or equivalent and on the heads, a good port and polish with an upgrade to 1.94 intake valves. A 60103 would even be a bit lumpier. Also remember you'll need to upgrade the springs to go with it. Alternately you can get a set of World Torquer S/R 305 heads. These come with the 1.94 intake already and will probably cost as much as having the port and polish work done on your current heads.

Also a 3" catback if that hasn't been done already.

Now, what year motor is this? Does it have a roller cam because those cam suggestions are for a flat tappet motor.

 

Thank you for your input Ozz. The car is 90 T/A w/ 5.0 305. I'm not sure what cam is in it. I have not had the engine apart yet. To my knowledge, the engine is original, other than the intake and exhaust mods that I have done. BTW it has Flowtech headers and 3 inch exhaust back to the muffler.

 

You will have a roller cam motor, they started those in 1986. I installed a roller motor in my 84 T/A so my cam in my 350 is a Lunati 60121. They've changed the numbers but if you search for the 60121 you'll find it. It's got a good strong mid range. It should be screaming in a 305.

You can keep your current intake, anything aftermarket really won't be that much better though an Edelbrock Performer or Performer Air Gap will show some gains. The heads and cam combined with the headers and catback will be what will really makes the difference. Don't forget the tune then, to go with the new cam, you'll need that to take the most advantage of your upgrades.

 

I have been reading up on tuning it myself. It seems like the better option than using a common chip. I have been an automotive tech for about 15 years now and have a pretty good working knowledge of engines but I don't have a lot of experience with performance upgrades. Although exciting, this is new to me and I want to make sure I'm doing it right.

 

I recently purchased an 85 iroc w/original motor and trans(5.0 tpi and 700r4,unsure of read end specs).I've decided to stay with original motor,now I'm seeking guidance on best performance upgrades(cam,headers,exhaust,heads,injectors,etc. Is the edelbrock hi-flo tpi kit worth buying?,what are some good upgrade to 700r trans?My personal research showed that my engines horsepower is rated at 215 and torque around 225. So to get those numbers around 350+ would be ideal.
Thanks

 

I was also going to build my 305 but decided against it. Summit Racing has some nice Edelbrock combination engine kits for the 305. Good luck! $$ Dont be disappointed in the end.

 

Only heads with 1.94" intake valves should be used in the small bore or else you run risk of hitting cylinder wall or just being heavily shrouded. Only aftermarket stuff i know of are the trickflow small bore 175's, ported 113's, or the 305 spec racing series castings by dart or brodix i believe... Late model 305 vortec castings could be used and really work well. Would clean up well.

Other trick would be offset drilling the bolt holes and/or valve guide/spacings to space them further away from cylinder wall. Then you can get a larger valve in there and open up the csa for lots more rpm and flow. Some even partly notch the block cylinder wall but that eats up alot of chamber volume. For aluminum heads you want more compression with bigger cams.

Regardless, if you go all out like that you should avoid tpi intakes or siamese custom runners for more rpm. Small cubes small bore needs rpm to make power. You can only get rpm out of certain head sizes and intake choices.

I want to do a pro filer 195 head cut for a sub 2" valve and see what i can wring out of a 305. 7000-7500 rpm range

 

BTW I called Edelbrock and their customer support gave me the info what will work for my application. A stand up company.