so I am swapping my 78 chevy truck to TPI out of a 89 camaro and to make it my tow rig so I am looking to make it the best one for towing not racing it's a flat tappet block with the L98 heads with screw in studs and guide plates, I will be running factory bottom end assuming 4 bolt main and stock tpi set up, will probably have 1.6 roller rockers later on but for now just factory rocker arms, assuming stock torque converter with th350 trans and unsure or rear end gear ratio at the moment but it's out of a big ten so I am assuming it decently low already. I want something that will be great for towing, and lengthy trips we often drive for about 2 hours to pick up a car so would like something that could get decent mileage.

Anyone got some info on this I don't just wanna go to compcams and pick the lowest rpm range for the XFI cam, but so far that's my best option

 

Howards makes a good low end cam that's pretty close to stock... Smogs easy. If you call them they are very customer oriented....

 

not concerned about smog I will have everything deleted (non emissions state and going on a 78 c big 10 which only came with a pcv valve for emission) but yeah I will hit them up thanks for the advice, I assume thy have a website I will check it out

 

so after some hours of research I am looking at http://www.summitracing.com/parts/hrs-cl112001-14 I haven't talked to the Howard tech like suggested they were already closed, I was thinking this cam because the power band is fairly low but as I don't ever plan on having it over 5k rpm I think it will be fine. Since those heads stop breathing at about .400 lift that would be the best without loosing too much to saturation. I still have a concern here according to summit this isn't for computer controlled cars, but I was told as long as the lobe separation was within 112-114° then it'll have enough vacuum to work with EFI, anyone have some .02 to throw in here?

 

Everyone's going to laugh at me, but I'd put a set of swirl port TBI heads on it instead of the L98s. And I'd stay at or below 205* duration at .050" lift.

 

aren't the l98 heads swirl port? I mean the heads came off my 91 T/A so I assumed they are l98 but the are clearly swirl port if you look into the valve chambers, not questioning your reasoning just trying to learn why do you recommend that for both the heads and the duration?

 

"Best" would involve stepping away from the flat tappets and getting into an 87 block so you can go cheap factory rollers and the. 86-up one piece rear main seal. Zero benefits to an 85-down shortblock.

The benefit is a shorter duration allowable for a given lift, ideal for a lower rpm torque application.

 

What engine management system are you planning to use? If the stock pcm, then pick a cam with another 8-10 degrees of duration or less. And keep the LSA 114 or higher, especially for a low rpm torque monster. If runnng a Mega or Microsquirt, then less LSA is an easy tune. I've run a 110 with plenty of vacuum to keep idle smooth.

I do agree with not putting in a cam that'll outrun the heads for your application. And keeping in mind that a wider LSA is going to make a better low end torque curve, I see no reason to put in a lopey cam.

But, as mentioned previously, finding another post '86 block to allow for a factory roller will be a tremendous benefit to what you are trying to accomplish IMO. The roller is going to add another 20-25hp and ft/lbs with an off the shelf cam. And keep in mind that when comparing a FT to a roller, that a durations between the two are not the same for the same level of performance. For example, if the original cam for the heads and EMS was a roller with 200/203 of duration and you want to put in a larger FT, then you're going to be in the area of 208/212 duration with a FT to be equivalent. So to add another 8-10 degrees of duration to put in a mildly larger FT cam has the potential to create a vacuum issue at idle if you're using the stock EMS. Basically, a factory roller block will eliminate this issue, along with increasing performance and most importantly, end the FT going flat concern.

My two cents (you said you were looking some-lol) and good luck.

 

Comp 200/206-110 472/480 Hyd. Roller With swirl-ports and stock TPI, no other 350 will out-torque it at low RPM.

 

350 powered thirdgens did not have the swirl port heads. Look at the casting number, last 3 digits specifically. 187 is 305 swirl port, 193 (from memory) is the 350 swirl port. Tell us the casting number on the heads and we can tell you what they are.

 

I am planning on running the stock ecm with a little tune on it I have the moats stuff from my race car and I wanna change the fan temp and get rid of the emission smog stuff anyways, I am running the block I got because well I got it and it works and finding another 350 around here let alone a roller is impossible. I still have the stock cam that came with my 91 (FT block) still in good shape but the lifters got out of order

 

I though it said 183 but must've been 193 for head casting

 

i DONT know much about howards, but have read a few times that theyre hyd flat tappet cams are re-grinds. maybe something to ask them about and clarify? do they parkerize them after re-grinding? would this introduce the problem of having to get different length pushrods? really not trying to bash them,...just a few questions that i would have before purchasing.