I have 91 Z-28 with a 305 TPI engine with stock heads SLP runners siamesed upper plenum and an adjustable fuel regulator. I also have a jet computer chip in it now and a 2400 stall TCIS torque converter . I just purchased a LPE 219 camshaft for a little over a hundred bucks. I was wondering how well this would work or if I would need a custom chip burned and possibly some porting on the heads.

 

you will need a really good tune to work that cam. its pretty aggressive in 350's let alone a 305.

you will need a good aftermarket base too, ported would help. abit more stall would work well too but not totally necessary. it will be somewhat sluggish down low but should move the car around.

once you get to 3000 rpms or so, it should take off hard and pull to 6000 rpms with the right intake, which i dont think TPI will support it. You will need to siamese those runners more, and the base too to get the rpms needed. A HSR would fit that motor well, but siamesed TPI should match that combo well.

Stock heads will only handle .480 lift without machine work to clearance it. Either get some new heads like the trickflow 175cc heads/AFR 180's or take your heads to a shop and have them do machine work on it. Screw in studs is a must. machine the pockets arent necessary if you run smaller dual valve springs like the Patriot Gold springs. They are ls1 style, 1.27-1.29 inch in diameter. They should fit right in and are good to .600 lift. Or better yet get 918 beehives. that cam is .560 i believe with 1.6 rockers.

Porting would really help that motor out. do some bowl work on the heads, minor clean up of the intake ports.

The tune will be the tricky part. its a fairly stout cam for a 305 but will work great once tuned. I would love to see that combo in action. It will definately want to rev and sound mean at idle with a good deal of lope

 

Thanks for the great info anyways I'm thinking on getting a TPIS lower intake manifold and possibly looking into some Afr heads. How far would you recommend that I siamese the runners and should I siamese the base at all. Do you know of any place that I could get a custom chip made.

 

i wouldnt siamese too far if you do try to siamese it. I'd stick with an inch or so if you do. mainly porting the base at the intake runner to head runner pinch is where you want to port. I think on a 305, the aftermarket TPI stuff is adequate, it only could use alittle porting but you dont have to if you dont want to. Also, You dont wanna go too deep with siamesing else you will lose low rpm power. I'd clean up the ports in the base if you get aftermarket base, and get some SLP runners that are already semi siamesed

Custom chips? pcmforless or fastchip is the only real places i know nowadays.

 

The slp runners I got are the newer type and are siamesed about an inch already I am going to port match the upper plenum and the runners to the mrg-146 gaskets and throw on a tpis base. Do you think that should be sufficient or should I go a little deeper. Do you think I could go with Afr 195 heads so I could use them on a 406 in a couple of years. If not do you think I could port the factory 416 heads to a sufficient level.

 

TPIS base and those runners will be fine for now. Possibly go in another 1/2-1" more on the top of the slp runner, thats about it.

AFR 195's are too much head on a 305. If your gonna build a 406 sometime in the future, get AFR's when you finalize the build combo for that 406 down the road. its not worth it for a 305 at the moment. i'd just keep the 416 heads and port those for the 305. you can get decent air out of those heads. It wont be optimal, but more than enough for that car for now. You want to keep compression up so the 305 style heads with the small 58cc chamber is what you want. possibly consider milling them to 54cc but watch for your ptv clearances. Work those heads to handle the lift of the cam as well. i'd stick to a 1.5 rocker arm to keep lift down.

This car will need a good tune tho so plan on getting some work done there.

 

You cant use the 195's as the valves are too large for the bore of the 305. They will hit eachother. As for the cam, I consider it mild. I ran it in my 350 with TF heads and a superram. Ran it on the stock injectors and stock 89 MAF chip. Ran good, but I could tell for more perfromance I needed a tune. Seeing you have a 91 , it probebly would need a tune as MAF is a little more forgiving then sd. Ended up getting 25+ MPG with that combo on the 03 PowerTour